Characterization of a Novel Frameshift Mutation Within the TRPS1 Gene Causing Trichorhinophalangeal Syndrome Type 1 in a Kindred Cypriot Family

Abstract

Trichorhinophalangeal syndrome (TRPS) is an extremely rare autosomal dominant multisystem disorder characterized by craniofacial and skeletal abnormalities. Three subtypes of TRPS have been described: TRPS type I, TRPS type II, and TRPS type III. Mutations in the TRPS1 gene can cause both TRPS type I and TRPS type III. Therefore, the genotype-phenotype correlation is crucial to determine the subtype. The current family study from Cyprus involves affected patients from 4 generations who presented with alopecia, unoperated umbilical hernia, caput quadratum, long philtrum, depressed nasal bridge, frontal bossing, pes planus, beaked nose, and some deformities in hands and feet. Sequence analysis of the TRPS1 gene revealed a novel c.2854_2858del (p.Asn952ArgfsTer2) frameshift variant leading to a premature stop codon. To the best of our knowledge, we report here the first case of a Turkish Cypriot family of 4 generations with a novel frameshift mutation leading to truncated protein in the TRPS1 gene causing TRPS type I clinical phenotype. Overall, as the genotype and phenotype correlation in TRPSI is still uncertain and complex, the present outcome can enhance our knowledge of this complicated, rare, and severe genetic disorder.