lyngstadaas syndrome lyngstadaas syndrome lyngstadaas syndrome, also known as severe dental aberrations in familial steroid dehydrogenase deficiency, is a rare autosomal recessive liver disease involving an enzyme (steroid dehydrogenase) deficiency and dental anomalies. the disease is named after the norwegian professor ståle petter lyngstadaas. lyngstadaas syndromeother namessteroid dehydrogenase deficiency-dental anomalies syndromethis condition is inherited in an autosomal recessive manner. cause lyngstadaas syndrome is an autosomal recessive liver disease. diagnosis epidemiology office of rare diseases listed lyngstadaas syndrome as a "rare disease". this means that lyngstadaas syndrome, or a subtype of lyngstadaas syndrome, affects less than 200,000 people in the us population. orphanet, a consortium of european partners, currently defines a condition rare when if affects 1 person per 2,000. they list lyngstadaas syndrome as a "rare disease".