Early onset or syndromic epilepsy

Gene: GTPBP1

I don't know

Comment on list classification: There are two unrelated patients reported with biallelic GTPBP1 variants and with epilepsy. Hence, this gene should be rated amber with the current evidence.

Created: 29 Jul 2026, 3:57 p.m. | Last Modified: 29 Jul 2026, 3:57 p.m.

Panel Version: 9.53

PMID:38118446 (2024) reported a cohort of 20 individuals from 16 families with distinct neurodevelopmental disorders (NDDs) and syndromic facial features and identified with biallelic variants in either GTPBP1 or GTPBP2 genes. Of these, four patients from three unrelated families were identified with homozygous variants in GTPBP1 gene. Two families have different NMD-predicted nonsense variants and the third has a missense variant, and all are absent from gnomad v4.1.1.

The shared clinical features of the syndrome include microcephaly, severe/ profound neurodevelopmental impairment, pathognomonic craniofacial features, and ectodermal defects. In addition, abnormal vision and/or hearing, progressive spasticity, choreoathetoid movements, refractory epilepsy, and brain atrophy were part of the core phenotype of this syndrome.

Epilepsy was reported in 2 patients from 2 families with GTPBP1 variants.

This gene has been associated with relevant phenotypes in OMIM (MIM #620888, last accessed 29 July 2026) and in Gene2Phenotype ('moderate' rating on the DD panel).
Sources: Literature

Created: 29 Jul 2026, 3:53 p.m.

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
Neurodevelopmental disorder with characteristic facial and ectodermal features and tetraparesis 1, OMIM:620888; neurodevelopmental disorder with characteristic facial and ectodermal features and tetraparesis 1, MONDO:0975745

Publications

• 38118446