Which genetic disorder is characterized by growth difficulties, insatiable hunger, low muscle tone, and cognitive/behavioral challenges?

Which genetic disorder is characterized by growth difficulties, insatiable hunger, low muscle tone, and cognitive/behavioral challenges?

• A. Fragile X syndrome
• B. Prader-Willi syndrome
• C. Down syndrome
• D. Williams syndrome

Answer: (B)

Growth difficulties paired with an insatiable appetite, low muscle tone from infancy, and notable cognitive and behavioral challenges point to Prader-Willi syndrome. This genetic condition typically starts with hypotonia and weak feeding in infancy, then progresses to an overpowering drive to eat, which can lead to severe obesity if not carefully managed. Short stature and growth hormone–related growth problems are common, and learning and behavior can include difficulties with impulse control and mood. The underlying cause involves loss of paternal gene function on chromosome 15 (15q11-q13), which can occur due to a deletion on the paternal chromosome, maternal uniparental disomy, or imprinting defects. Other syndromes have their own distinct hallmarks—for example, Fragile X often features broader developmental and social differences, Down syndrome includes intellectual and physical features not defined by hyperphagia, and Williams syndrome has a different profile of social and cardiovascular traits—so the combination described fits Prader-Willi most closely.

Growth difficulties paired with an insatiable appetite, low muscle tone from infancy, and notable cognitive and behavioral challenges point to Prader-Willi syndrome. This genetic condition typically starts with hypotonia and weak feeding in infancy, then progresses to an overpowering drive to eat, which can lead to severe obesity if not carefully managed. Short stature and growth hormone–related growth problems are common, and learning and behavior can include difficulties with impulse control and mood.

The underlying cause involves loss of paternal gene function on chromosome 15 (15q11-q13), which can occur due to a deletion on the paternal chromosome, maternal uniparental disomy, or imprinting defects. Other syndromes have their own distinct hallmarks—for example, Fragile X often features broader developmental and social differences, Down syndrome includes intellectual and physical features not defined by hyperphagia, and Williams syndrome has a different profile of social and cardiovascular traits—so the combination described fits Prader-Willi most closely.