Disorder
Bowen-Conradi syndrome

Clinical Characteristics

General description (for patients):

This is a malformation syndrome characterized by unusual facies with a prominent nose, small jaw, and a small head.  The joints may be stiff.  Growth is delayed and death in infancy is common.  Patients may have an unusual curvature to their little fingers.

Medical description (for healthcare providers):

Bowen-Conradi syndrome is a malformation condition found extensively among all Hutterite communities.  Microcephaly, prominent nose, micrognathia, clinodactyly, cryptorchidism, failure to thrive and general developmental delay seem to be characteristic.  Joints are stiff and contractures may develop.  Death usually occurs in the first months of life.

Genetics:

A locus containing the presumed mutation causing this apparent autosomal recessive condition has been mapped to chromosome 12 (12p13.3).  A c.400A>G substitution causes a malfunction in a ribosomal biogenesis protein, EMG1. This disorder has been reported in multiple sibships among all three major Hutterite leuts in Canada with a carrier frequency that may be as high as 10%.

Management:

None.

General supportive care.

Prognosis:

Death usually occurs in the first year of life.

Specialists and specialty centers:

Pediatrician, dysmorphologist.

References:

Bowen, P., and Conradi, G.J.:  Syndrome of skeletal and genitourinary anomalies with unusual facies and failure to thrive in Hutterite sibs.  Birth Defects Orig. Art. Ser. XII: 101-108, 1976. PubMed ID: 974244

Lowry, R.B., Innes, A.M., Bernier, F.P., McLeod, D.R., Greenberg, C.R., Chudley, A.E., Chodirker, B., Marles, S.L., Crumley, M.J., Loredo-Osti, J.C., Morgan, K., and Fujiwara, T.M.:  Bowen-Conradi syndrome: a clinical and genetic study.  Am. J. Med. Genet. 120A:  423-428, 2003. PubMed ID: 12838567

Lamont, R.E., Loredo-Osti, J.C., Roslin, N.M., Mauthe, J., Coghlan, G., Nylen, E., Frappier, D., Innes, A.M., Lemire, E.G., Lowry, R.B., Greenberg, C.R., Triggs-Raine, B.L., Morgan K., Wrogemann, K., Fujiwara, T.M., and Zelinski, T.:  A locus for Bowen-Conradi syndrome maps to chromosome region 12q13.3.  Am. J. Med. Genet. 132A: 136-143, 2005. PubMed ID: 15578624

Armistead, J., Khatkar, S., Meyer, B., Mark, B.L., Patel, N., Coghlan, G., Lamont, R.E., Liu, S., Wiechert, J., Cattini, P.A., Koetter, P., Wrogemann, K., Greenbeerg, C.R., Entian, K.D., Zelinski, T., Triggs-Raine, B.:  Mutation of a gene essential for ribosome biogenesis. EMG1, causes Bowen-Conradi syndrome.  Am. J. Hum. Genet. 84: 728-739, 2009.  PubMed: 19463982

Flanagan, J.D., Stein, Q.P., Mroch, A.R., Deberg, K.L., Crotwell, P.L., and Keppen, L.D.:  Bowen-Conradi: a common Hutterite condition that mimics trisomy 18.  S.D. Med. 65: 221-223, 2012.  PubMed: 22856010.

Resources:

NIH Office of Rare Diseases