@Article{Laaraje2025,
journal="Pediatric Endocrinology Diabetes and Metabolism",
issn="2081-237X",
volume="31",
number="4",
year="2025",
title="Od niedoboru hormonu wzrostu do zespołu Kleefstra 2: ponowna ocena diagnostyczna  opornego na leczenie niskiego wzrostu",
abstract="We report a 12-year-old girl with developmental delay, dysmorphic features, and short stature initially diagnosed with growth hormone deficiency at age 7. Despite appropriate growth hormone treatment for four years with documented insulin-like growth factor-1 (IGF-1) normalization (64→241.7 ng/ml), growth velocity remained suboptimal (5–6 cm/year vs. expected 7–8 cm/year). Clinical examination revealed triangular facies, hypertelorism, gingival hyperplasia, moderate intellectual disability, and delayed language development (first words at 3 years). Whole exome sequencing identified a novel de novo heterozygous KMT2C mutation (c.7444_7445insCC, p.Phe2482Serfs*34), confirming Kleefstra-2 syndrome diagnosis. Treatment resistance despite a biochemical response suggests possible post-receptor IGF-1 resistance, potentially related to epigenetic dysregulation. This represents the first documented case of growth hormone deficiency with detailed endocrine characterization in Kleefstra-2 syndrome, expanding the phenotypic spectrum and highlighting the importance of considering genetic syndromes in treatment-refractory short stature.",
author="Laaraje, Azzeddine
and Abassi, Khadija
and Radi, Abdelilah
and Abilkassem, Rachid",
pages="209--214",
doi="10.5114/pedm.2025.158552",
url="http://dx.doi.org/10.5114/pedm.2025.158552"
}