Abstract
BACKGROUND: The pathogenic mutation of short stature homeobox (SHOX) gene is one of the main genetic causes of short stature in children, with an incidence rate of 1/1000~1/2000 and the main clinical manifestations are short stature and (or) limb skeletal abnormalities. SHOX gene mutations are mostly large deletions of regulatory sequence genes, while exon mutations are relatively rare. The pathogenic rate of mutations occurring in exon 5 is only 1/50 000~1/100 000. This study reviewed the clinical data of a child with SHOX gene mutation in exon 5, and analyzed the clinical phenotype, pathogenesis, diagnosis, treatment and prognosis of SHOX gene mutation in combination with relevant literature at home and abroad. CASE PRESENTATION: The patient was an 8-year-old girl with a height of 105.2 cm (-4.31 standard deviations). Her sitting height/height ratio was 56.8% (>55.5%), and she exhibited high-arched palate, irregular dentition, micrognathia, short fingers, and a normal growth hormone stimulation test. Whole-exome sequencing was performed, and Sanger sequencing was used for site validation. The sequencing results revealed a heterozygous mutation of c.577G > A in exon 5 of the SHOX gene, inherited from the father. The clinical symptoms of the proband were consistent with the phenotype of short stature idiopathic familial associated with SHOX gene mutations. The father, grandfather, uncle, and sister of the proband all had the c.577G > A heterozygous mutation. Therefore, the clinical diagnosis was childhood short stature caused by SHOX gene defects. The SHOX: c.577G > A mutation is likely to be the genetic etiology of familial idiopathic short stature in this family, and this novel mutation enriches the mutation spectrum of the SHOX gene. CONCLUSION: This is the first case report of familial idiopathic dwarfism caused by mutation at the c.577G > A locus of exon 5 of SHOX gene in the world. This novel mutation enriches the mutation spectrum of the SHOX gene. It is important to emphasize genetic testing, including the SHOX gene, in patients with familial idiopathic short stature and to provide timely growth hormone therapy to individuals with short stature caused by SHOX gene mutations in order to improve their adult height.