Expanding the clinical and molecular features of tricho-rhino-phalangeal syndrome with a novel variant

Tow bone mineral density (BMD) was identified in two TRPS2 family members presenting with bone fracture, and growth hormone deficiency was detected in two patients. The exact prevalence of TRPS is unknown; the estimated prevalence is Q.2-1/100,000.1'2 It was first described in 1966 by Giedion, and less than 250 TRPS patients have been reported.34 There are two clinical subtypes of TRPS; one of them is TRPS type 1 (TRPS1) (OMIM #190350) caused by pathogenic variants in the TRPS1 gene located on chromosome 8q23.3, and the other one is TRPS type 2 (Langer-Giedion syndrome, LGS), (OMIM #150230), a contiguous gene deletion syndrome is caused by submicroscopic deletion of the chromosomal segment 8q23.3-8q24.11, containing TRPS1, RAD21, and EXT1. A different subtype of TRPS has also been described; however, TRPS type 3 is now accepted within the spectrum of TRPS1 with more severe brachydactyly and short stature.25 TRPS1 gene is a zinc finger transcription factor expressed in cartilage, kidneys, and hair follicles that represses GATA-regulated genes and regulates bone perichondrium mineralization, chondrocyte proliferation, differentiation, and apoptosis.6/7TRPSl has high penetrance and wide phenotypic variability. Molecular Analysis Molecular karyotyping was performed using the DNA samples of patients obtained from peripheral whole blood.