SAT-230 - Growth Hormone Deficiency in A Child with 22Q11.2 Duplication Initially Suspected to Have Familial Short Stature

Background: Short stature in children with short parents is frequently attributed to familial short stature, which may delay recognition of underlying genetic conditions. Chromosomal abnormalities such as 22q11.2 duplication syndrome can present with subtle or variable features and have important implications for medical surveillance.

Case Presentation: We describe a 10-year-old male referred for evaluation of short stature and weight loss, initially presumed to have familial short stature given that both non-consanguineous parents were 4 ft 9 in tall. His history was notable for poor school performance and speech delay requiring therapy. Initial evaluation demonstrated normal thyroid function and insulin-like growth factor-1 levels (169 ng/mL; reference range 76–366 ng/mL). Bone age was delayed by approximately one year. Growth hormone stimulation testing revealed an inadequate peak growth hormone level of 7.6 ng/mL, consistent with growth hormone deficiency. Due to associated developmental concerns, genetic testing was pursued and identified a duplication of chromosome 22q11.2. Parental testing confirmed maternal inheritance of the duplication. Given the known association between 22q11.2 duplication syndrome and congenital heart defects, the patient underwent cardiology evaluation; electrocardiogram and echocardiogram were normal.

Discussion: 22q11.2 duplication syndrome is a variably expressive condition that is inherited in approximately half of reported cases. Affected individuals may have developmental delay, hypotonia, failure to thrive, and congenital anomalies, including cardiac defects. Short stature may be misattributed to familial factors, potentially delaying diagnosis and appropriate multidisciplinary evaluation.

Conclusion: This case highlights the importance of considering genetic testing in children with short stature and developmental concerns, even when parental heights suggest familial short stature. Identification of 22q11.2 duplication syndrome alters clinical management, prompts targeted surveillance, and provides critical information for family counseling.

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