Growth hormone therapy in Turner syndrome: Do cytogenetic subtypes influence outcomes?

Turner syndrome (TS) is a chromosomal disorder caused by complete or partial loss of one X chromosome, occurring in approximately 1 in 2500 live female births. Short stature, resulting from haploinsufficiency of the short stature homeobox-containing (SHOX) gene, absence of a pubertal growth spurt, and ovarian insufficiency are hallmark features. Recombinant human growth hormone (GH) therapy remains the mainstay of management, increasing adult height by approximately 5-8cm. This review examines how cytogenetic subtypes influence GH response, focusing on 45,X monosomy, mosaicism, and structural abnormalities such as isochromosome Xq and ring X. Patients with 45,X monosomy often show a favorable initial response but a more rapid decline in growth velocity, whereas mosaic patients maintain better long-term outcomes. Structural variants involving Xp loss exhibit similarly attenuated responses. Overall, differences between cytogenetic subtypes tend to diminish over time, with age at therapy initiation, treatment duration, and timing of pubertal induction exerting a greater influence on final height outcomes.