Table 2.

Diagnostic criteria for Alström syndrome and Bardet-Biedl syndrome.

	Major criteria/Primary features	Minor criteria/Secondary features	Other supportive evidence	Diagnosis
Bardet-Biedl syndrome	Cone-rod dystrophy	Speech disorder/delay
	Postaxial polydactyly	Strabismus/cataracts/astigmatism
	Truncal obesity	Brachydactyly/syndactyly
	Learning disabilities	Developmental delay
	Hypogonadism in males or genital abnormalities in females	Polyuria/polydipsia (nephrogenic diabetes insipidus)
	Renal anomalies	Ataxia/poor coordination/imbalance		4 major criteria OR 3 major + 2 minor criteria
		Mild hypertonia (especially lower limbs)
		Diabetes mellitus
		Dental crowding/hypodontia/small dental roots/high-arched palate
		Cardiovascular anomalies
		Hepatic involvement
Alström syndrome	ALMS 1 mutation in 1 allele and/or family history of Alström syndrome	Obesity and/or insulin resistance and/or type 2 diabetes	Recurrent pulmonary infections
	Vision (legal blindness, history of nystagmus in infancy/childhood, cone and rod dystrophy by electroretinogram	History of dilated cardiomyopathy/congestive heart failure	Normal digits
		Hearing loss	History of developmental delay	2 major + 2 minor criteria
		Hepatic dysfunction	Hyperlipidemia
		Renal failure	Scoliosis
		Short stature	Flat wide feet	OR
		Males – hypogonadism	Hypothyroidism
		Females – irregular menses and/or hyperandrogenism	Hypertension	1 major + 4 minor criteria
			Growth hormone deficiency Alopecia
			Recurrent urinary tract infections or urinary dysfunction