Which syndrome is characterized by hypogonadism, mental retardation, short stature, pectus excavatum, and webbed neck in a child?

The syndrome characterized by hypogonadism, mental retardation, short stature, pectus excavatum, and webbed neck in a child is Noonan syndrome. This genetic condition is often caused by mutations in genes involved in the RAS/MAPK signaling pathway, leading to the various physical and developmental features observed.

Individuals with Noonan syndrome typically exhibit short stature, congenital heart defects, and distinctive facial features, which can include a webbed neck and pectus excavatum. Hypogonadism is also a key feature, particularly in males, and may lead to developmental delays or learning disabilities, which can be referred to as mental retardation in a clinical context.

While Turner syndrome is associated with short stature and features such as a webbed neck, it typically presents in females and includes characteristics like ovarian dysgenesis rather than the broader spectrum of developmental issues found in Noonan syndrome. Prader-Willi syndrome primarily involves early childhood hypotonia, obesity, and behavioral issues rather than the specific combination of features listed. Bardet-Biedl syndrome is characterized by obesity, retinal dystrophy, polydactyly, and renal anomalies rather than the symptoms described.

Thus, the specific combination of symptoms such as hypogonadism,