X-linked chondrodysplasia punctata type 1 (CDPX1) - case report with atypical phenotype

Abstract

Chondrodysplasia punctata (CDP) is a group of bone dysplasias characterized by punctate calcifications in the cartilage, mainly epiphyseal. Among the various forms of CDP, the X-linked form is rare and has been described in 50 male patients in the literature. The aim of this study is to describe an atypical case of CDPX1 and compare it with previous literature. Preschooler, male, four years old, born full-term, small for gestational age and with no similar cases in the family. He developed disproportionate short stature, eutrophy, cervical and dorsal scoliosis with pectus carinatum, slight asymmetry in the lower limbs, ocular hypertelorism with blue-gray sclera and hair loss. He did not present fractures or bone pain and had neuropsychomotor development appropriate for his age. The exams showed no changes in the osteometabolic profile or in pituitary hormones. The karyotype was 46,XY and the genetic panel for skeletal dysplasias showed a hemizygous pathogenic variant in the ARSL gene (Arylsulfatase L) chrX:2.934.859 C>T (p.Trp581* ENST00000381134) diagnosed with X-linked chondrodysplasia punctata type 1. CDPX1 is directly related to the deficiency of ARSL enzyme activity, which can result in changes in neuropsychomotor development, hearing loss and episodes of respiratory failure. However, these characteristics were not presented by the proband. Thus, the proband has a milder form of CDPX1. Early diagnosis of skeletal dysplasias such as CDPX1 is important for adequate outpatient follow-up, family counseling and prevention of the development of long-term comorbidities.

Keywords

• genetics
• chondrodysplasia punctata
• child