Clinical and Genetic Study on 48 Children with Short Stature of Unknown Etiology / 中山大学学报(医学科学版)

ABSTRACT

ObjectiveTo explore the clinical features and causative genes of short stature children with unknown etiology， providing evidence for precise clinical diagnosis and treatment. MethodsThe study recruited children with suspected but undiagnosed short stature from the pediatric endocrinology department in our hospital between January 2018 and August 2022. A retrospective analysis was performed on the clinical manifestations， laboratory test and whole exome sequencing （WES） results. Causative genes were classified and analyzed according to different pathogenic mechanisms. ResultsA total of 48 children （30 boys and 18 girls） were enrolled， aged 7.73 ± 3.97 years， with a height standard deviation score （ HtSDS） of -3.63 ± 1.67. Of the patients， 33 （68.8%） suffered from facial anomalies， 31 （64.6%） from skeletal abnormalities， 26 ［54.2%， 61.5% of whom born small for gestational age （SGA）］ from perinatal abnormalities， 24 ［50.0%， 87.5% of whom with growth hormone （GH） peak concentration below normal］ from endocrine disorders and 21（43.8%） had a family history of short stature. Laboratory tests showed that GH peak concentration following stimulation test was （9.72 ± 7.25） ng/mL， IGF-1 standard deviation score was -0.82 ± 1.42， the difference between bone age and chronological age was -0.93 ± 1.39 years. Of the 25 cases with mutant genes found by WES， 14 （56.0%） had pathogenic mutation， 6 （24.0%） likely pathogenic mutation， and 5 （20.0%） mutation of uncertain significance. Pathogenic and likely pathogenic variants were identified in 14 genes， including 10 affecting intracellular signaling pathways （PTPN11， RAF1， RIT1， ARID1B， ANKRD11， CSNK2A1， SRCAP， CUL7， SMAD4 and FAM111A） and 4 affecting extracellular matrix （ECM） components or functions （ACAN， FBN1， COL10A1 and COMP）. ConclusionsA rare monogenic disease should be considered as the possible etiology for children with severe short stature accompanied by facial anomalies， disproportionate body types， skeletal abnormalities， SGA， GH peak concentration below normal and a family history of short stature. WES played an important role in identifying the monogenic causes of short stature. This study indicated that affecting growth plate cartilage formation through intracellular signaling pathways and ECM components or functions was the main mechanism of causative genes leading to severe short stature in children. Further research may help discover and study new pathogenic variants and gene functions.