Diagnostic Criteria for Prader-Willi Syndrome
Major criteria |
Characteristic facial features (may include almond-shaped eyes, down-turned mouth, narrow bifrontal diameter, strabismus, thin upper lip; see Figures 1 and 2) |
Developmental delay |
Feeding problems/failure to thrive during infancy |
Hypogonadism (may include cryptorchidism, hypoplastic scrotum, and small testes in males; hypoplastic labia minora and clitoris in females; and pubertal deficiency) |
Infantile central hypotonia |
Rapid weight gain between 1 and 6 years of age |
Minor criteria |
Decreased fetal movement and infantile lethargy |
Esotropia, myopia |
Hypopigmentation |
Narrow hands with straight ulnar border |
Short stature (compared with family members) |
Skin picking |
Sleep disturbance/sleep apnea |
Small hands and feet |
Speech articulation defects |
Thick, viscous saliva |
Typical behavioral problems |
note: Score 1 point for each major criterion and 0.5 point for each minor criterion. A diagnosis of Prader-Willi syndrome should be suspected in children younger than three years with a score of at least 5; and in children three years and older with a score of at least 8, with 4 points from major criteria. Supportive criteria (no points) include high pain threshold, decreased vomiting, temperature control problems, scoliosis, kyphosis, early adrenarche, osteoporosis, unusual skill with jigsaw puzzles, and normal neuromuscular studies.
Information from reference 4.