Prepair 1000+

Gene: YIF1B

Green List (high evidence)

Kaya-Barakat-Masson syndrome (KABAMAS) is a severe autosomal recessive neurodevelopmental disorder characterized by profoundly impaired global development, peripheral spasticity, dystonia, impaired intellectual development with absent speech, poor eye contact, and feeding difficulties, resulting in poor overall growth, sometimes with microcephaly.

Additional more variable features include early-onset seizures, ocular anomalies, foot deformities, and nonspecific brain imaging findings, such as thin corpus callosum and cerebral, cerebellar, or pontine atrophy. Some patients may die in infancy or early childhood.

The phenotype of individuals with biallelic protein-truncating variants tends to be more severe compared to that of individuals with biallelic missense variants. This might be due to residual activity of YIF1B (GeneReviews PMID: 39265055).

I believe this gene should be green for Prepair, currently Red (see MM review).

Created: 21 Jan 2025, 3:23 a.m. | Last Modified: 21 Jan 2025, 3:23 a.m.

Panel Version: 1.1257

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
Kaya-Barakat-Masson syndrome MIM#619125

Publications

• 32006098
• 26077767
• 33103737
• 36948290
• 34373908
• 39265055

Green List (high evidence)

DEFINITIVE gene-disease association by ClinGen. Over 20 individuals now reported in the literature.

Created: 18 Aug 2024, 2:59 a.m. | Last Modified: 18 Aug 2024, 2:59 a.m.

Panel Version: 1.168

6 individuals (from 5 families) with biallelic YIF1B truncating variants reported. Presenting features: hypotonia, failure to thrive, microcephaly (5/6), severe global DD and ID as well as features suggestive of a motor disorder (dystonia/spasticity/dyskinesia). Seizures were reported in 2 unrelated individuals (2/6). MRI abnormalities were observed in some with thin CC being a feature in 3. Affected individuals were found to be homozygous for truncating variants (4/5 families being consanguineous). The following 3 variants were identified (NM_001039672.2) : c.186dupT or p.Ala64fs / c.360_361insACAT or p.Gly121fs / c.598G>T or p.Glu200*. Yif1B KO mice demonstrate a disorganized Golgi architecture in pyramidal hippocampal neurons (Alterio et al 2015 - PMID: 26077767). Functional/network analysis of genes co-regulated with YIF1B based on available RNAseq data, suggest enrichement in in genes important for nervous system development and function.

Created: 18 Aug 2024, 2:57 a.m. | Last Modified: 18 Aug 2024, 2:57 a.m.

Panel Version: 1.168

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
Kaya-Barakat-Masson syndrome, MIM# 619125

Publications

• 33103737
• 32006098
• 36948290
• 34373908