[Genetic analysis of a pedigree with primary hypertrophic osteoarthropathy]

Objective: To analyze the clinical and genetic features of primary hypertrophic osteoarthropathy (PHO). Methods: The clinical data of one Chinese pedigree of PHO, namely pachydermoperiostosis (PDP) were collected.Blood samples were drawn from the propositus and other family members.DNA was extracted and genetic analysis was performed by Sanger method after PCR.The sequencing data of HPGD gene exons were analyzed by alignment with sequences from National Center for Biotechnology Information (NCBI). Results: (1)The propositus represented symptoms in childhood including clubbing fingers, sweating, seborrhea, joint swelling and so on.Periosteal thickening and bone hyperplasia were found by X-ray. (2)The homozygous mutation named c. 310_311delCT in propositus, which located in the third exon of HPGD, was identified.His parents carried the same heterozygous mutation, while his sister did not inherit any mutation of this gene. (3)The prediction of spatial structure of proteins revealed that the mutant proteins had about 60% discrepancy compared with wild-type protein, losing a lot of motifs responsible for combining with coenzyms and prostaglandin E(2), as well as active sites of enzymes. Conclusions: The clinical manifestations and imaging findings are helpful to diagnose PDP. Moreover gene mutation analysis ensures the diagnosis.The structure and function of HPGD gene mutation induce 15-hydroxy prostaglandin dehydrogenase mutation, contributing to the occurrence of PDP.