michels caskey syndrome michels caskey syndrome michels caskey syndrome is a rare disorder that combines spinal and skeletal abnormalities, especially of the thumbs, with abnormal or absent female reproductive organs. examples include the absence of a cervix and upper vagina or abnormalities of the uterus or vagina. symptoms may also include scoliosis and primary amenorrhea. synonyms include hypoplastic thumb mullerian aplasia, and mullerian aplasia with unilateral hypoplasia of the thumbs and skeletal spine deformities. stratton-parker syndromeother namesmullerian aplasia with hypoplastic thumbsspecialtyorthopedic