The first familial case of inherited intellectual developmental disorder with dysmorphic facies and behavioral abnormalities (IDDFBA) with a novel FBXO11 variant.

Intellectual developmental disorder with dysmorphic facies and behavioral abnormalities (IDDFBA) caused by germline de novo variants in FBXO11 was recently recognized as a novel intellectual disability (ID) syndrome through reverse phenotyping after whole-exome sequencing (WES). Fewer than 50 disease-causing de novo FBXO11 variants in IDDFBA are reported thus far. Here, we present the first report of a family showing autosomal dominantly inherited IDDFBA, harboring a novel heterozygous variant in FBXO11 (c.2401_2405dup;p. Gly803Leufs*6) identified by WES. In this family, the mother and two daughters showed mild ID and mild facial dysmorphism. This finding is expected to increase our understanding of the genotype-phenotype of IDDFBA and to facilitate genetic counseling for the disorder caused by FBXO11.