Clinical diagnosis of the Prader-Willi Syndrome can be made using a score based on physical, mental and emotional findings. Genetic testing can be used to confirm the diagnosis.
Findings are divided into:
(1) major criteria
(2) minor criteria
(3) supportive findings that increase certainty in diagnosis but which are not scored
|
Major Criteria |
Points |
|
infantile central hypotonia |
1.0 |
|
infantile feeding problems, failure to thrive |
1.0 |
|
rapid weight gain between 1 and 6 years of age |
1.0 |
|
characteristic facial features (narrow bifrontal diameter, almond-shaped palpebral fissures, narrow nasal bridge, downturned mouth with thin upper lip) |
1.0 |
|
hypogonadism with genital hypoplasia and/or pubertal deficiency |
1.0 |
|
developmental delay or mental retardation |
1.0 |
where:
• The original criteria from 1993 included cytogenetic abnormality with chromosome 15 (deletion 15q11-13). Modern techniques have made genetic testing diagnostic.
• The original criteria from 1993 included hyperphagia, food foraging and obsession with food.
|
Minor Criteria |
Points |
|
decreased fetal movement and infantile lethargy |
0.5 |
|
typical behavior problems (temper tantrums, stubbornness, manipulative behavior, obsessive-compulsive behavior, difficulty with change in routine, lying, stealing, aggressive) |
0.5 |
|
sleep disturbance, sleep apnea |
0.5 |
|
short stature for family by age 15 years |
0.5 |
|
hypopigmentation |
0.5 |
|
small hands and feet for height age |
0.5 |
|
narrow hands with straight ulnar border |
0.5 |
|
esotropia, myopia |
0.5 |
|
thick, viscous saliva |
0.5 |
|
speech articulation defects |
0.5 |
|
skin picking |
0.5 |
|
Supportive Criteria |
Points |
|
high pain threshold |
0 |
|
decreased vomiting |
0 |
|
temperature control problems |
0 |
|
scoliosis and/or kyphosis |
0 |
|
early adrenarche (normal adrenarche around 8 years of age) |
0 |
|
osteoporosis |
0 |
|
unusual skill with jigsaw puzzles |
0 |
|
normal neuromuscular studies |
0 |
subscore for major criteria =
= SUM(points for major criteria)
subscore for minor criteria =
= SUM(points for minor criteria)
total points =
= (points for major criteria) + (points for minor criteria)
|
Clinical Diagnosis |
Total Points |
Major Criteria (Holm, 1993) |
Major Criteria (Cassidy, 2001) |
|
age <= 3 years of age |
>= 5 |
>= 4 |
>= 3 |
|
age > 3 years of age |
>= 8 |
>= 5 |
>= 4 |
where:
• The fewer major criteria in Cassidy may reflect the reduction in number.
Specialty: Genetics
