Wiedemann–Steiner Syndrome (WDSTS) is a rare autosomal dominant disorder caused by KMT2A variants, characterized by distinctive facial features, hypertrichosis, developmental delay, and short stature, with some patients exhibiting Growth Hormone Deficiency (GHD). We report a 5-year-4-month-old Chinese boy presenting with global developmental delay, short stature (104.5 cm, <−2 SD), long dense eyelashes, mild ptosis, hypertrichosis, and skin hyperpigmentation. Whole exome sequencing identified a novel de novo KMT2A frameshift mutation (c.917delC, p. P306Lfs*7), confirming WDSTS. Endocrine evaluation revealed GHD with a peak GH level of 6.71 ng/mL. The patient was treated with weekly recombinant human Growth Hormone (rGH) at 0.2 mg/kg. After 15 months, his height increased from 105.0 cm to 119.2 cm (+14.2 cm), with improvement from the 3rd to the 45th percentile and an initial growth velocity of 3–5 cm per 3 months. IGF-1 levels increased appropriately, and bone age progressed in accordance with chronological age. No adverse effects were observed. This case highlights the presence of GHD in WDSTS and supports rGH therapy as a safe and effective intervention for improving linear growth, emphasizing the importance of routine endocrine evaluation in affected patients.

Shiling Yan graduated from Chengdu Medical College, have nearly 10 years of experience in pediatric clinical practice and completed advanced training at Zhejiang University Children’s Hospital. Specialize in common pediatric diseases and have extensive experience in endocrine disorders, including short stature, precocious puberty, diabetes, obesity, and thyroid diseases. Currently serve as a member of Chongqing pediatric endocrinology and puberty study groups.