Growth response and genetic factors in SGA children: a study on rGH therapy and copy number variations

Objective: Small for gestational age (SGA) is a heterogeneous condition influenced by fetal, placental, maternal, and genetic factors. While most SGA children experience catch-up growth within the first two years, up to 10-15% remain short-statured and may require growth hormone (GH) therapy. This study evaluated the clinical characteristics, genetic factors, and responses to recombinant GH (rGH) therapy in non-syndromic SGA children with persistent short stature. Material and Methods: We retrospectively analyzed 36 non-syndromic short-statured children born SGA who were evaluated in a tertiary center. Genetic testing, including karyotyping and microarray analysis for copy number variations (CNVs), was performed. Growth response to rGH therapy was assessed in 19 patients over a three-year period. Results: Among the 19 patients receiving rGH therapy, the mean height SDS improved from -3.04±0.58 at baseline to -2.07±0.67 after three years, with an average gain of 0.97 SDS. CNVs were identified in 6 patients (16.66%), with several pathogenic or likely pathogenic variants, including deletions and duplications in regions associated with growth and developmental disorders. Conclusion: A significant proportion of non-syndromic SGA children with persistent short stature exhibit CNVs, underscoring the genetic complexity of this condition. rGH therapy effectively improves growth outcomes, but individual responses vary. These findings highlight the need for routine genetic screening and personalized treatment strategies to optimize care for SGA children.