Pathogenic variants in TRAPPC4 cause a severe progressive paediatric multisystem neurodevelopmental disorder with epilepsy, spasticity, and brain atrophy (NEDESBA; OMIM 618741).
The majority of affected individuals harbour the same homozygous variant in a well-conserved splice donor site in TRAPPC4, hg19:chr11:g.118890966A>G; TRAPPC4: NM_016146.5; c.454+3A>G. According to gnomAD, the allele frequency for this variant is 3.85e-4, meaning that the carrier frequency of TRAPPC4 c.454+3A>G is 1 in every 1300 individuals. There are two other reported variants in TRAPPC4.
Inheritance is autosomal recessive.
TRAPPC4