A novel homozygous mutation in FGFR3 causes tall stature, severe lateral tibial deviation, scoliosis, hearing impairment, camptodactyly, and arachnodactyly.

[achondroplasia]

Most reported mutations in the FGFR 3 gene are dominant activating mutations that cause a variety of short -limbed bone dysplasias including achondroplasia and syndromic craniosynostosis . We report the phenotype and underlying molecular abnormality in two brothers , born to first cousin parents . The clinical picture is characterized by tall stature and severe skeletal abnormalities leading to inability to walk , with camptodactyly , arachnodactyly , and scoliosis . Whole exome sequencing revealed a homozygous novel missense mutation in the FGFR 3 gene in exon 12 (NM _000142 .4 :c .1637 C >A : p .(Thr 546 L ys )). The variant is found in the kinase domain of the protein and is predicted to be pathogenic . It is located near a known hotspot for hypochondroplasia . This is the first report of a homozygous loss -of-function mutation in FGFR 3 in human that results in a skeletal overgrowth syndrome .

Diseases
Validation

Diseases presenting "arachnodactyly" symptom

achondroplasia

cohen syndrome

homocystinuria without methylmalonic aciduria

papillon-lefÃ¨vre syndrome

This symptom has already been validated