Uner Tan described a hereditary syndrome of quadrupedalism in several Turkish families. The first patients were described in 1917.
Several families have been identified in different parts of Turkey.
Inheritance: not defined
Clinical features:
(1) consanguinity
(2) quadrupedalism
(3) mental retardation
(4) dysarthria or absence of speech
(5) cerebellar ataxia
So far 2 types have been described, Type I without and Type II with infantile hypotonia.
