EIF3F-related neurodevelopmental disorder: refining the phenotypic and expanding the molecular spectrum
Background: An identical homozygous missense variant in EIF3F, identified through a large-scale genome-wide sequencing approach, was reported as causative in nine individuals with a neurodevelopmental disorder, characterized by variable intellectual disability, epilepsy, behavioral problems and sensorineural hearing-loss. To refine the phenotypic and molecular spectrum of EIF3F-related neurodevelopmental disorder, we examined independent patients.
Results: 21 patients were homozygous and one compound heterozygous for c.694T>G/p.(Phe232Val) in EIF3F. Haplotype analyses in 15 families suggested that c.694T>G/p.(Phe232Val) was a founder variant. All affected individuals had developmental delays including delayed speech development. About half of the affected individuals had behavioral problems, altered muscular tone, hearing loss, and short stature. Moreover, this study suggests that microcephaly, reduced sensitivity to pain, cleft lip/palate, gastrointestinal symptoms and ophthalmological symptoms are part of the phenotypic spectrum. Minor dysmorphic features were observed, although neither the individuals' facial nor general appearance were obviously distinctive. Symptoms in the compound heterozygous individual with an additional truncating variant were at the severe end of the spectrum in regard to motor milestones, speech delay, organic problems and pre- and postnatal growth of body and head, suggesting some genotype-phenotype correlation.
Conclusions: Our study refines the phenotypic and expands the molecular spectrum of EIF3F-related syndromic neurodevelopmental disorder.
Keywords: Altered muscular tone; Behavioral difficulties; Deafness; EIF3F gene; Neurodevelopmental disorder; Short stature.
Hüffmeier U, Kraus C, Reuter MS, Uebe S, Abbott MA, Ahmed SA, Rawson KL, Barr E, Li H, Bruel AL, Faivre L, Tran Mau-Them F, Botti C, Brooks S, Burns K, Ward DI, Dutra-Clarke M, Martinez-Agosto JA, Lee H, Nelson SF; UCLA California Center for Rare Disease, Zacher P, Abou Jamra R, Klöckner C, McGaughran J, Kohlhase J, Schuhmann S, Moran E, Pappas J, Raas-Rothschild A, Sacoto MJG, Henderson LB, Palculict TB, Mullegama SV, Zghal Elloumi H, Reich A, Schrier Vergano SA, Wahl E, Reis A, Zweier C. EIF3F-related neurodevelopmental disorder: refining the phenotypic and expanding the molecular spectrum. Orphanet J Rare Dis. 2021 Mar 18;16(1):136. doi: 10.1186/s13023-021-01744-1.