N NEXMIF Foundation Est. 2025 · 501(c)(3) non-profit
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A rare X-linked condition · approximately 350 patients identified worldwide

Rewriting
what's possible
for NEXMIF

The NEXMIF Foundation is a non-profit organization advancing the science of NEXMIF-related syndrome — a rare X-linked disorder whose features, including autism, epilepsy, and developmental delay, vary depending on how each individual is affected by the gene. Our mission is to serve the public interest by raising awareness of the NEXMIF gene mutation and mobilizing funding to support vital scientific research, therapeutic development, and educational outreach.

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Locus: Xq13.2–q13.3 4 exons · ~192 kb gene span NEXMIF
~350
Patients identified through the international community*
*via the XLID98 Facebook group; peer-reviewed literature documents a smaller subset3
ASD
Recognized as a Category 1 high-confidence autism gene by SFARI17
83%
Experience seizures, often drug-resistant1
99%
Present with developmental delay1
§ 01 / The Condition

An under-recognized neurodevelopmental disorder on the X chromosome

NEXMIF-related disorder is a rare X-linked neurodevelopmental condition caused by pathogenic variants in the NEXMIF gene — Neurite EXtension and MIgration Factor — located at the Xq13.2–q13.3 boundary on the X chromosome, spanning approximately 192 kb across 4 exons that encode a 1,516–amino acid neuronal protein.2312 The gene encodes a neuron-specific protein essential for proper neurite outgrowth, neuronal migration, and synaptic formation during brain development.45

Affected individuals typically present with autism spectrum disorder, seizures (often drug-resistant epilepsy, including myoclonic and absence seizures with eyelid myoclonia) and developmental delay. Additional features include hypotonia, gait and balance disturbances, behavioral abnormalities, challenges with sensory needs, speech impairment ranging from delayed to absent language, and vision defects (such as strabismus and torpedo maculopathy31). In addition, individuals may have multi-system findings such as gastrointestinal (gastrointestinal reflux, constipation), sleep abnormalities, endocrine, and dysmorphic features. NEXMIF is recognized as a high-confidence (Category 1) autism-implicated gene by the Simons Foundation Autism Research Initiative (SFARI).1

Because the gene is X-linked, males generally exhibit more severe developmental impact, while heterozygous females show striking phenotypic variability — from nearly asymptomatic carriers to severely affected individuals with intractable epilepsy. This variability is thought to be driven, in part, by X-chromosome inactivation patterns.71

Despite its small known population, NEXMIF-related disorder has emerged as a clinically and scientifically tractable target. Loss-of-function is the dominant disease mechanism, animal models exist,8 and the gene's biology is increasingly well-characterized9 — making it a strong candidate for precision and individualized therapeutic strategies.

Gene at a glance

NEXMIF on the X chromosome

NEXMIF Xq13.2–q13.3 p q
Locus Xq13.2–q13.3
Gene span ~192 kb
Exons 4
Protein 1,516 aa
Constraint pLI = 1 / LOEUF = 0.2
Inheritance X-linked

OMIM gene #300524 · disease #300912 · HGNC:29433 · UniProt Q5QGS0

What is NEXMIF?

Key facts at a glance · NEXMIF-related disorder (historically called XLID98 or KIAA2022 syndrome)

NEXMIF-related disorder is a rare X-linked neurodevelopmental disorder caused by changes in the NEXMIF gene.

Why this matters

NEXMIF is essential for healthy brain development and communication between neurons. When the gene is not working properly, brain development and function are affected.

X-chromosome inactivation (XCI) matters

In females, one X chromosome is randomly inactivated in each cell. Because of this, symptoms can vary widely — from mild to severe — even within the same family.

Genetic cause

Caused by variants (mutations) in the NEXMIF gene. Most are loss-of-function variants (nonsense, frameshift, splice-site, large deletions) that reduce or eliminate the function of the protein.

X

X-linked inheritance

NEXMIF is located on the X chromosome. Both males and females can be affected. Males are often more severely affected on average, but females can also be significantly affected.

Role in the brain

NEXMIF is crucial for normal brain development. It plays an important role in synapse formation, neuronal connectivity, and communication.

Clinical features

Common features include developmental delay, epilepsy, autism spectrum traits, speech/language delays, and motor challenges.

Variable symptoms in females

Due to X-chromosome inactivation, females can show a wide range of symptoms — from mild learning or language difficulties to severe neurodevelopmental challenges, including epilepsy.

Rarity & impact

NEXMIF-related disorder is rare, but it has a significant impact on individuals and families. More research is bringing us closer to targeted therapies and better outcomes.

Adapted with appreciation from educational materials presented by Dr. Gabriele Lignani (UCL Queen Square Institute of Neurology) to the NEXMIF community.

§ 01.5 / A history of names

One gene, many names

Over two decades, NEXMIF has been known by half a dozen different identifiers as the genetics community has refined both its nomenclature and its language. Each name reflects a chapter in how the field came to understand this gene.

  • KIAA2022 Original cDNA clone identifier from the Kazusa DNA Research Institute — the gene's first name before its function was known
  • MRX98 Original historical OMIM designation assigned when first linked to non-syndromic X-linked intellectual disability (2004); no longer preferred
  • XLID98 X-Linked Intellectual Disability 98 — current OMIM disease designation, reflecting modern, person-centered terminology
  • ID98 · XLID, Cantagrel type Alternate short-form and eponymous names recognizing the gene's discoverer
  • XPN · KIDLIA Earlier protein-level designations from functional studies before the official rename
  • NEXMIF · NEXMIF encephalopathy Current HGNC-approved gene name (2018) and clinical name, reflecting the protein's function in Neurite EXtension and MIgration
§ 01.2 / History

From an unknown cDNA to a named disease

The story of NEXMIF illustrates how a once-obscure X-linked locus became a recognized, internationally-collaborative neurodevelopmental disorder over two decades.

2004
First disease association. Cantagrel and colleagues identify variants in KIAA2022 in males with non-syndromic X-linked intellectual disability, linking the locus to the OMIM-designated MRX98 locus — the standard nomenclature of the era. The gene entry is catalogued at OMIM #300524.2
2013
Phenotype expanded in males. Van Maldergem et al. describe a broader male phenotype including poor or absent speech, autistic features, and subtle dysmorphisms, and show impaired neurite outgrowth in KIAA2022-deficient neurons.4
~2013
Disease renamed: MRX98 → XLID98. As medical genetics adopts more accurate, person-centered language, OMIM and the broader community adopt X-Linked Intellectual Disability 98 (XLID98) as the preferred disease name — preserving the numeric designation while updating the terminology. The disease entry is later catalogued at OMIM #300912.
2014–2015
Autism and brain biology. Several groups (Kuroda, Charzewska, Moyses-Oliveira, Farach & Northrup) characterize de novo gene-disruptive variants in both males and females.1011 The protein is recognized as a regulator of neurite extension and migration.5
2016
The female phenotype emerges. de Lange et al. publish the first large series of 14 affected heterozygous females with developmental delay and intractable generalized epilepsy — reshaping understanding of the disorder's sex-specific patterns.7
2018
Gene symbol renamed to NEXMIF. Following a decade of functional work, the HUGO Gene Nomenclature Committee (HGNC) formally renames the gene from KIAA2022 to NEXMIF — Neurite EXtension and MIgration Factor — finally giving it a function-based name. The disease entry retains the XLID98 designation, but clinicians increasingly use “NEXMIF encephalopathy” or “NEXMIF-related syndrome.”12
2019
Mouse models published. Gilbert et al. characterize Nexmif knockout mice, demonstrating reduced sociability, repetitive grooming, and learning & memory deficits — establishing a tractable preclinical platform.8
2021
Landmark international cohort. Stamberger, Møller, Mefford, Scheffer and the international NEXMIF consortium publish the largest study of NEXMIF encephalopathy (n = 87) in Genetics in Medicine, delineating two dominant clinical pictures across sexes.1
2022–2025
Mechanism and modifiers. New work explores hippocampal CA1 dynamics,13 E/I imbalance in autism-related NEXMIF biology, beta-cell phenotypes,14 and the expanding mutational spectrum9 — including novel female variants15 and rare multi-system presentations.16
Nov 2025
First proof-of-concept for therapeutic rescue. Merth and Man at Boston University demonstrate that reactivating the silenced Nexmif allele on the inactive X chromosome can restore NEXMIF protein expression in heterozygous female mice. Using both a pharmacological approach (5-aza-2′-deoxycytidine combined with resveratrol) and a more precise CRISPR activation (CRISPRa) strategy, the team showed that turning on the dormant healthy copy can correct mosaic NEXMIF deficiency — opening the door to X-reactivation as a therapeutic approach for female patients.18
2025
The NEXMIF Foundation is founded. To accelerate research, build a unified patient registry, and create the infrastructure for n-of-1 trials and precision therapeutics.
2025–present
Lead Scientific Partner
Dr. Jagdeep Walia (Queen's University) joins as Principal Investigator and lead scientific collaborator. The Walia Lab brings its AAV-based gene therapy platform and expertise in rare CNS disorders to NEXMIF, and is actively developing and maintaining NEXMIF mouse models that provide critical preclinical infrastructure for the foundation's therapeutic mission. Dr. Walia has been the foundation's most consistent and committed scientific supporter from its earliest days and remains its lead research partner.29
§ 02 / Epidemiology

An ultra-rare disorder — and almost certainly under-diagnosed

Because NEXMIF was only formally linked to disease in 2004 and renamed in 2018, diagnosis depends almost entirely on access to whole-exome or whole-genome sequencing. NEXMIF is now routinely included on diagnostic gene panels for autism spectrum disorder, developmental delay, and developmental and epileptic encephalopathies. As clinical genetic testing has become more accessible, the number of identified cases has grown rapidly — but most patients still receive their diagnosis after years of unexplained developmental delay, autistic features, and seizures.17

Global prevalence

Published clinical literature has documented several hundred individuals with pathogenic NEXMIF variants worldwide, distributed across case reports, cohort studies, and systematic reviews.31 The international XLID98 Facebook community (administered by Kristi Bakker) has independently identified approximately 350 patients — meaningfully more than the peer-reviewed clinical literature, and a more accurate reflection of the diagnosed community to date. True global prevalence remains unknown and is almost certainly higher still, as the condition requires next-generation sequencing for confirmation.9

Sex distribution

Reported cohorts contain more females than males — the inverse of most X-linked disorders.1 This likely reflects ascertainment bias from severe seizure phenotypes in females,7 with under-recognition of mildly-affected male relatives and asymptomatic female carriers.

Phenotypic spectrum

In the largest published cohort (n=87): 99% developmental delay/ID and 83% seizures, with generalized myoclonic and absence seizures predominating. Autism spectrum disorder and autistic features are core to the disorder — NEXMIF is classified as a Category 1 ASD gene by SFARI. Males show more severe cognitive impairment and ASD features; females show more frequent, often drug-resistant epilepsy.117

Common symptoms beyond the core triad

Frequently reported features

Seizures

Often drug-resistant; generalized

Myoclonic, absence, eyelid myoclonia with absence, and atonic seizures predominate. Frequently difficult to fully control with medication.1

Movement issues

Ataxia, unstable gait

Difficulty with coordination, balance, and walking. Some individuals never achieve independent walking; others walk with an unsteady, wide-based gait.1

Attention difficulties

ADHD · hyperactivity

Attention-deficit/hyperactivity disorder is commonly reported, including hyperactivity, impulsivity, and difficulty maintaining focus across tasks.6

Reflux

GERD · gastroesophageal reflux disease

Gastroesophageal reflux is frequently reported, particularly in infancy and early childhood, and may require medical or surgical management.1

Microcephaly

Smaller-than-average head size

A head circumference below the typical range for age and sex. Often present from infancy and reflects altered early brain development.4

Hypotonia

Lower-than-average muscle tone

Reduced muscle tone, often present from infancy. Can affect feeding, posture, motor milestones, and contribute to delayed walking.14

Not every individual has every symptom. Severity varies significantly between patients, and males and females are affected differently. Share your child's profile →
§ 03 / Research Landscape

The science behind a cure-directed strategy

Major Research Program Studying NEXMIF

The flagship international registry and natural history program through which most NEXMIF research currently flows.

Natural History · Biorepository

Simons Searchlight

Simons Foundation Autism Research Initiative (SFARI)

An international online research program building a continually-growing natural history database, biorepository, and resource network for over 175 rare genetic neurodevelopmental disorders — with NEXMIF as one of its actively-studied genes. Families anywhere in the world can participate remotely.3

simonssearchlight.org/nexmif →
International Consortium

The International NEXMIF Encephalopathy Consortium

Coordinated through Filadelfia Epilepsy Hospital, Denmark · University of Melbourne, Australia

The collaborative network behind the 2021 landmark cohort of 87 patients (Stamberger et al., Genetics in Medicine).1 Continues to recruit globally for genotype-phenotype, EEG, and outcome studies.

Read the landmark paper →

Academic Research Groups Studying NEXMIF

The NEXMIF Foundation's lead research collaborator, alongside additional academic groups whose work is relevant to NEXMIF biology.

Lead Research Partner · Principal Investigator

The Walia Lab

Queen's University · Department of Pediatrics, Kingston, Ontario

Led by Dr. Jagdeep Walia, the Walia Lab serves as the principal scientific partner and primary research collaborator for the NEXMIF Foundation. Dr. Walia is the lead investigator advancing our therapeutic mission and has been the foundation's most consistent and committed scientific supporter from its earliest days.

The lab maintains a highly translational gene-therapy platform: it develops AAV-based gene therapies for rare central nervous system disorders, with proven expertise in lysosomal storage diseases, creatine deficiency syndromes, and the production and characterization of disease-specific mouse models. The Walia Lab is actively developing and maintains NEXMIF mouse models, providing the foundation with critical preclinical infrastructure for evaluating gene therapy approaches in NEXMIF biology.

The lab has contributed directly to the published NEXMIF literature with detailed case reports characterizing the male phenotype29 and continues to expand the field's understanding of NEXMIF-related disorder through ongoing translational work.

Visit walialab.com →

Additional academic groups with work relevant to NEXMIF biology

Neurobiology

The Man Lab

Boston University

Generated the first Nexmif knockout mouse model8 and published proof-of-concept work on X-reactivation rescue in heterozygous female mice.18

people.bu.edu/hman →
Gene Therapy · Epilepsy

The Lignani Lab

UCL Queen Square Institute of Neurology

Develops gene therapy approaches for intractable neurological disease, with a focus on drug-resistant epilepsy.

lignanilab.com →
Theoretical framework

A theoretical framework for the treatment pipeline

An illustrative pathway showing how precision-medicine approaches for a rare genetic disorder like NEXMIF could move from biological samples to individualized therapeutic candidates.

Important note

This framework is theoretical and illustrative. It represents how the field broadly approaches precision-medicine development for rare genetic conditions — it is not a description of clinical trials or therapies currently available to NEXMIF patients. The science required to move from concept to clinic remains in early stages, and many open questions remain.

1

Collect biological samples

Clinicians collect skin or blood samples from individuals with NEXMIF variants, providing the biological material needed for research.

2

Develop cell models

Researchers use those samples to develop patient-specific cell models in the lab — living cells that carry the same variant and reflect the person's own biology.

3

Study the variant's effects

Scientists analyze how the NEXMIF gene and its protein behave in these cells, pinpointing how the variant disrupts normal function.

4

Engineer a precision treatment

Using these insights, researchers engineer a treatment designed to correct or compensate for the specific genetic change.

5

Preclinical testing

Candidate treatments undergo rigorous testing in cells and animal models to evaluate effectiveness and safety before any clinical use in patients.

Similar precision-medicine approaches are already in preliminary clinical testing — and in some cases early clinical use — for related rare neurogenetic conditions such as Rett syndrome and spinal muscular atrophy, demonstrating that frameworks like this one can transition from theory to therapy. The NEXMIF Foundation supports the kind of precision-medicine research that may one day translate into therapies for affected individuals. Every donation accelerates the underlying science required to make pipelines like this one a clinical reality.

Our priority program

Building the infrastructure for n-of-1 trials in NEXMIF

For ultra-rare conditions like NEXMIF, traditional trial designs are infeasible. The NEXMIF Foundation is funding the variant-specific preclinical work, registry depth, regulatory groundwork, and clinical partnerships needed to make individualized therapies — including ASOs and gene-based approaches — possible for our community.

Support this program →
§ 04 / Global Community

International groups worth connecting with

Rare disease progress is community work. These are the patient organizations, family groups, and registries that have built the NEXMIF community to where it is today. We are proud to collaborate with all of them.

🇺🇸

XLID98 Foundation

United States · Global Scope

Supports families of individuals affected by XLID98 (KIAA2022/NEXMIF/MRX98) worldwide. Focuses on community-building, family education, scientific collaboration, awareness, and research funding.

xlid98.org
🇺🇸

Simons Searchlight

International · Online

The premier international registry and natural history study for NEXMIF and 175+ other rare genetic neurodevelopmental conditions. Free, remote participation for families anywhere.

simonssearchlight.org
🌐

XLID98 / NEXMIF Facebook Group

International · led by Kristi Bakker

A private, family-led Facebook community of more than 1,700 members worldwide, founded and administered by Kristi Bakker. Approximately 350 patients have been identified through this community to date — nearly double the number known to peer-reviewed clinical literature — making it the most comprehensive informal census of the NEXMIF population in existence.

Join the group →
🇪🇺

EpiCARE European Reference Network

European Union

The official EU reference network for rare and complex epilepsies, including NEXMIF encephalopathy. Connects clinicians and researchers across European member states.

epi-care.eu
§ 05 / Patient Portal

Every patient counts. Especially yours

When only a few hundred patients are known to medicine worldwide, every family that joins the registry meaningfully accelerates the science. Your participation directly enables natural-history publications, regulatory submissions, and the design of future precision therapies — including n-of-1 trials.

Join the NEXMIF Foundation patient portal to be matched with research opportunities, kept informed of treatment developments, and connected with other families on the same journey.

  • Secure storage of your or your child's genetic and clinical information, accessible only to you.
  • Be matched to research studies and n-of-1 trial opportunities relevant to your specific variant.
  • Early access to the foundation's research updates, family conference invitations, and clinical guidance.
  • Connect privately with other families whose loved ones carry related variants.
  • HIPAA-aligned data practices — you control how your information is shared with researchers.
Request received. If your account is registered, the foundation will send portal access instructions.

Forgot your password? Reset it here. Trouble logging in? Email mavaraagrawal@gmail.com.

Thank you for joining. We'll be in touch within 48 hours to verify your registration and provide portal access.
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By submitting, you consent to be contacted by the NEXMIF Foundation. Your information is stored securely and is never shared with researchers, pharmaceutical companies, or third parties without your separate, explicit consent. You may withdraw at any time.

§ 07 / References

The science we stand on

The information presented on this site is drawn from peer-reviewed literature, curated genetic databases, and authoritative patient organizations. All references are listed below with direct links to the source. We update this list as the field advances; corrections are welcomed at mavaraagrawal@gmail.com.

Key Clinical & Cohort Studies

  1. Stamberger H, Hammer TB, Gardella E, Vlaskamp DRM, ... Møller RS, Scheffer IE. NEXMIF encephalopathy: an X-linked disorder with male and female phenotypic patterns. Genetics in Medicine. 2021;23(2):363–373. doi.org/10.1038/s41436-020-00988-9
  2. Cantagrel V, Lossi AM, Boulanger S, Depetris D, Mattei MG, Gecz J, et al. Disruption of a new X linked gene highly expressed in brain in a family with two mentally retarded males. Journal of Medical Genetics. 2004;41(10):736–742. doi.org/10.1136/jmg.2004.021626
  3. de Lange IM, Helbig KL, Weckhuysen S, Møller RS, Velinov M, Dolzhanskaya N, et al. De novo mutations of KIAA2022 in females cause intellectual disability and intractable epilepsy. Journal of Medical Genetics. 2016;53(12):850–858. pmc.ncbi.nlm.nih.gov/articles/PMC5264224
  4. Van Maldergem L, Hou Q, Kalscheuer VM, Rio M, Doco-Fenzy M, Medeira A, et al. Loss of function of KIAA2022 causes mild to severe intellectual disability with an autism spectrum disorder and impairs neurite outgrowth. Human Molecular Genetics. 2013;22(16):3306–3314. pmc.ncbi.nlm.nih.gov/articles/PMC3723314
  5. Kuroda Y, Ohashi I, Naruto T, Ida K, Enomoto Y, Saito T, et al. Delineation of the KIAA2022 mutation phenotype: two patients with X-linked intellectual disability and distinctive features. American Journal of Medical Genetics Part A. 2015;167A(6):1349–1353. doi.org/10.1002/ajmg.a.36992
  6. Charzewska A, Rzońca S, Janeczko M, Nawara M, Smyk M, Bal J, et al. A duplication of the whole KIAA2022 gene validates the gene role in the pathogenesis of intellectual disability and autism. Clinical Genetics. 2015;88(3):297–299. doi.org/10.1111/cge.12528
  7. Anastasescu CM, Gheorman V, Godeanu SV, Cojocaru A, Iliuta FP, Stepan MD, Gheorman V. KIAA2022/NEXMIF c.1882C>T (p.Arg628*) Variant in a Romanian Patient with Neurodevelopmental Disorders and Epilepsy: A Case Report and Systematic Review. Life. 2025;15(3):497. doi.org/10.3390/life15030497
  8. Zhu Y, Cui F, Ouyang X, Guo J, Liu Y, Li N, Yang Q, Li Y, Liu L. Intellectual disorder type 98 caused by a novel NEXMIF variant: a case report and literature review. Frontiers in Medicine. 2026;13:1757682. doi.org/10.3389/fmed.2026.1757682
  9. Wang L, Huang Y, Liu X. NEXMIF pathogenic variant in a female child with epilepsy and multiple organ failure: a case report. Translational Pediatrics. 2023;12(6):1278–1287. doi.org/10.21037/tp-22-435

Mechanism & Basic Science

  1. Gilbert J, O'Connor M, Templet S, Moghaddam M, Di Via Ioschpe A, Sinclair A, Zhu LQ, Xu W, Man HY. NEXMIF/KIDLIA Knock-out Mouse Demonstrates Autism-Like Behaviors, Memory Deficits, and Impairments in Synapse Formation and Function. Journal of Neuroscience. 2020;40(1):237–254. doi.org/10.1523/JNEUROSCI.0222-19.2019
  2. Gilbert J, Man HY. The X-Linked Autism Protein KIAA2022/KIDLIA Regulates Neurite Outgrowth via N-Cadherin and δ-Catenin Signaling. eNeuro. 2016;3(5):ENEURO.0238-16.2016. doi.org/10.1523/ENEURO.0238-16.2016
  3. Mount RA, Athif M, O'Connor M, Saligrama A, Tseng HA, Sridhar S, Zhou C, Bortz E, San Antonio E, Kramer MA, Man HY, Han X. The autism spectrum disorder risk gene NEXMIF over-synchronizes hippocampal CA1 network and alters neuronal coding. Frontiers in Neuroscience. 2023;17:1277501. doi.org/10.3389/fnins.2023.1277501
  4. Stekelenburg C, Blouin JL, Santoni F, Zaghloul N, O'Hare EA, Dusaulcy R, et al. Loss of Nexmif results in the expression of phenotypic variability and loss of genomic integrity. Scientific Reports. 2022;12:13815. doi.org/10.1038/s41598-022-17845-1
  5. Merth K, Man HY. Reactivation of the X-linked Nexmif Gene Corrects Mosaic NEXMIF Deficiency in Heterozygous Female Mice. bioRxiv preprint. 2025. Man Laboratory, Boston University. doi.org/10.1101/2025.11.29.691251

Gene & Variant Databases

  1. HUGO Gene Nomenclature Committee (HGNC). Gene Symbol Report: NEXMIF (HGNC:29433). European Bioinformatics Institute. genenames.org · HGNC:29433
  2. SFARI Gene. Human Gene Module: NEXMIF. Simons Foundation Autism Research Initiative. gene.sfari.org/database/human-gene/NEXMIF
  3. Online Mendelian Inheritance in Man (OMIM). Intellectual Developmental Disorder, X-linked, Syndromic 98; MRXS98. Johns Hopkins University. omim.org/entry/300912 · gene entry 300524
  4. UniProt Consortium. NEXMIF · Neurite Extension and Migration Factor · Q5QGS0. European Bioinformatics Institute. uniprot.org/uniprotkb/Q5QGS0
  5. Human Protein Atlas. NEXMIF (KIAA2022, KIDLIA, MRX98, XPN) protein expression summary. proteinatlas.org/ENSG00000050030-NEXMIF
  6. ClinGen. NEXMIF (HGNC:29433) gene-disease validity, dosage sensitivity, and genomic structure. Cytoband: Xq13.3; MANE Select transcript NM_001008537.3 (ENST00000055682.12); 4 coding exons spanning approximately 192 kb; pLI = 1, LOEUF = 0.2 (strong constraint against loss-of-function). search.clinicalgenome.org · HGNC:29433
  7. Ensembl Genome Browser. NEXMIF (ENSG00000050030) — gene summary. Genomic coordinates: X:74,732,856–74,925,472 (GRCh38), confirming gene span across the Xq13.2–q13.3 boundary. ensembl.org · ENSG00000050030

Patient Registries & Family Organizations

  1. Kalra A, Bijarnia-Mahay S, Rai A, Verma I, Saviour P, Verma J. Clinical spectrum of KIAA2022/NEXMIF pathogenic variants in males and females: Report of three patients from Indian kindred with a review of published patients. Journal of the Neurological Sciences. 2020;416:117025. doi.org/10.1016/j.jns.2020.117025
  2. XLID98 Foundation. Family-led foundation supporting individuals affected by XLID98 (KIAA2022/NEXMIF/MRX98) worldwide. Registered charity in Canada. xlid98.org
  3. Online Mendelian Inheritance in Man (OMIM). Entry #300912: Intellectual Developmental Disorder, X-linked 98 (XLID98) — the canonical disease entry, sometimes called “X-linked intellectual disability, Cantagrel type.” Johns Hopkins University. omim.org/entry/300912
  4. EpiCARE. European Reference Network on rare and complex epilepsies. epi-care.eu

Additional Selected Clinical Reports

  1. Lambert N, Dauve C, Ranza E, Makrythanasis P, Santoni F, Sloan-Béna F, et al. Novel NEXMIF pathogenic variant in a boy with severe autistic features, intellectual disability, and epilepsy, and his mildly affected mother. Journal of Human Genetics. 2018;63(8):847–850. doi.org/10.1038/s10038-018-0459-2
  2. Farach LS, Northrup H. KIAA2022 nonsense mutation in a symptomatic female. American Journal of Medical Genetics Part A. 2016;170(3):703–706. doi.org/10.1002/ajmg.a.37479
  3. Lorenzo M, Stolte-Dijkstra I, van Rheenen P, Smith RG, Scheers T, Walia JS. Clinical spectrum of KIAA2022 pathogenic variants in males: Case report of two boys with KIAA2022 pathogenic variants and review of the literature. American Journal of Medical Genetics Part A. 2018;176(6):1455–1462. doi.org/10.1002/ajmg.a.38667
  4. Moyses-Oliveira M, Guilherme RS, Meloni VA, Di Battista A, de Mello CB, Bragagnolo S, et al. X-linked intellectual disability related genes disrupted by balanced X-autosome translocations. American Journal of Medical Genetics Part B. 2015;168(8):669–677. doi.org/10.1002/ajmg.b.32355
  5. Alarcon-Martinez T, Khan A, Myers KA. Torpedo Maculopathy Associated with NEXMIF Mutation. Molecular Syndromology. 2019;10(4):229–233. doi.org/10.1159/000498835
  6. Athanasakis E, Licastro D, Faletra F, Fabretto A, Dipresa S, Vozzi D, et al. Next generation sequencing in nonsyndromic intellectual disability: from a negative molecular karyotype to a possible causative mutation detection. American Journal of Medical Genetics Part A. 2014;164A(1):170–176. doi.org/10.1002/ajmg.a.36274
  7. Webster R, Cho MT, Retterer K, Millan F, Nowak C, Douglas J, et al. De novo loss of function mutations in KIAA2022 are associated with epilepsy and neurodevelopmental delay in females. Clinical Genetics. 2017;91(5):756–763. doi.org/10.1111/cge.12854
  8. Chen S, Deng X, Xiong J, Chen B, He F, Yang L, et al. NEXMIF mutations in intellectual disability and epilepsy: A report of 2 cases and literature review. Zhong Nan Da Xue Xue Bao Yi Xue Ban. 2022;47(3):265–270. pubmed.ncbi.nlm.nih.gov/35545418
  9. Qi H, Pan D, Zhang Y, Zhu Y, Zhang X, Fu T. NEXMIF Combined with KIDINS220 Gene Mutation Caused Neurodevelopmental Disorder and Epilepsy: One Case Report. Actas Españolas de Psiquiatría. 2024;52(4):588–594. pmc.ncbi.nlm.nih.gov/articles/PMC11319755
Disclaimer

Content on this site is for informational and educational purposes only and is not a substitute for medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider for questions about a medical condition. The NEXMIF Foundation makes every reasonable effort to ensure references are current and accurately cited; please notify us of any errors at mavaraagrawal@gmail.com.

§ 08 / Stay Connected

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§ 09 / Share Your Story

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§ 10 / Contact

Get in touch

We welcome inquiries from families, clinicians, researchers, journalists, donors, and anyone interested in supporting the NEXMIF community. We do our best to respond to every message within two business days.

For urgent medical questions, please consult your healthcare provider directly — the NEXMIF Foundation provides community and research support, not medical advice.

Primary contact
mavaraagrawal@gmail.com
EIN 39-4335407
Tax status 501(c)(3) non-profit organization
Established 2025
General inquiries
mavaraagrawal@gmail.com

Questions about the foundation, partnerships, media, and general information.
Research & science
mavaraagrawal@gmail.com

For researchers, clinicians, and questions about our scientific program, grants, or collaborations.
Patient portal
mavaraagrawal@gmail.com

Registry sign-ups, account help, and questions from NEXMIF families about participating.
Donations & giving
mavaraagrawal@gmail.com

Major gifts, recurring donations, matching gifts, planned giving, and tax-receipt questions.