Spontaneous Growth in Patients with Noonan Syndrome

Abstract

Noonan syndrome (NS) is a syndrome with great phenotypical resemblance to Turner syndrome (TS). However, there are significant differences between the two disorders. Amongst others cardiac abnormalities in NS usually affect the right side, moderate mental retardation is frequent and hypogonadism commonly affects boys. In NS both genders are affected in equal frequency (total incidence approx. 1: 1,000). Autosomal dominant inheritance occurs in approx. 20 %, but the molecular genetic basis is obscure. There is a disease-specific growth pattern in NS: size at birth is normal, mean height follows approximately the 5th centile of normal children, pubertal growth spurt is delayed and diminished. The pathogenesis of the growth disorder is unknown. Disease-specific growth standards are presented which are useful when evaluating the response to growth-promoting treatment.

Growth hormone therapy in pre‐pubertal children with Noonan syndrome: first year growth response and comparison with Turner syndrome

“…Growth retardation involving both height and weight is a relatively consistent aspect of Noonan syndrome (NS) (1,2). Adult height averages 162.5 t-5.4cm in males and 152.7 ?…”

“…Adult height averages 162.5 t-5.4cm in males and 152.7 ? 5.7 in females (2). Phenotypically, NS is strikingly similar to Turner syndrome (TS) and is therefore sometimes called the male TS.…”