Clinical phenotype and genetic analysis of a child featuring short stature and multiple skeletal dysplasia

Abstract

To analyze the clinical phenotype and genetic basis for a child featuring familial short stature. A child who was admitted to Huzhou Maternal and Child Health Care Hospital on October 7, 2021 for growth retardation and pectus carinatum was selected as the study subject. Physical exam and medical imaging was performed. The child was subjected to whole exome sequencing, and candidate variants were verified by Sanger sequencing and bioinformatic analysis. The child, a 1-year-old male, had manifested with slightly short stature (Z = -2.03), midfacial dysplasia, and multiple skeletal dysplasia such as pectus carinatum, irregular vertebral morphology, and defect of lumbar anterior bones. His mother, maternal grandmother and great-maternal grandfather also had short stature. WES revealed that the child has harbored a heterozygous c.2858dupA (p.Asp953GlufsTer476) frameshifting variant of the ACAN gene, which was inherited from his mother. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c.2858dup (p.Sp953Glufster476) variant was classified as likely pathogenic (PVS1+PM2_Supporting). The patient has shown marked improved height after receiving 11 months of treatment with human recombinant growth hormone (supplemental dose) starting from 20 months of age. The ACAN: c.2858dup (p.Asp953GlufsTer476) variant probably underlay the pathogenesis of short stature in this child.