ADDUCTED THUMB SYNDROME
General description (for patients): This is a rare syndrome with unusual abnormalities. Infants are born with variable features such as cleft palate, small heads, an abnormally shaped skull, and clasped thumbs. They may appear stiff-faced and floppy. The combination of brain and respiratory malformations may lead to early death.
Medical description: This is an extremely rare syndrome of brain and respiratory tract malformations incompatible with life beyond a few months. Infants have microcephaly with craniostenosis and dysmyelination of the brain. The thumbs are adducted and do not extend during the Moro reflex. There may be generalized hypotonia, cleft palate (or at least a high arch), arthrogryposis, swallowing and breathing difficulties from respiratory tract malformations, hypertrichosis, and a myopathic stiff face.
GENETICS: Evidence for autosomal recessive inheritance comes from three Amish sibships whose parents all shared a common ancestor. No genomic studies have been done on these families. The relationship of this disorder to the X-linked MASA syndrome (#303350), another adducted thumb disorder, is unknown. Respiratory disease and CNS dysmyelination are not part of the MASA syndrome which seems to be a form of spastic paraplegia with less severe neurological signs than found in the Amish cases.
TREATMENT: No treatment is available.
PROGNOSIS: One infant died at 18 days of age and another at 3 months.
ANCILLARY TREATMENTS AND SUPPORT: General supportive care, aspiration prevention, optimal respiratory care.
SPECIALISTS AND SPECIALTY CENTERS: Neurologist, pulmonologist, pediatrician.
Christian, J.C., Andrews, P.A., Conneally, P.M., and Muller, J.: The adducted thumbs syndrome: an autosomal recessive disease with arthrogryposis, dysmyelination, craniostenosis, and cleft palate. Clin. Genet. 2: 95-103, 1971. PubMed ID: 5116596
Kunze, J., Park, W., Hansen, K.-H., and Hanefeld, F.: Adducted thumb syndrome: report of a new case and a diagnostic approach. Europ. J. Pediat. 141: 122-126, 1983. PubMed ID: 6662143