"Holoprosencephaly-polydactyly" (pseudotrisomy 13) syndrome: expansion of the phenotypic spectrum.
Analysis of familial cases of the so called "holoprosencephaly-polydactyly" ("pseudotrisomy 13") syndrome shows that neither holoprosencephaly, nor polydactyly are obligatory manifestations of this condition. This review of previous case reports shows that each of these anomalies is only found in approximately 60% of affected sibs, and therefore these sentinel abnormalities are not required for diagnosis. We propose a widening of the phenotypic spectrum of this syndrome and consideration of the use of an eponomic name, such as the Cohen-Gorlin syndrome, or clear recognition that the sentinel findings of holoprosencephaly and polydactyly are not essential for diagnosis. We propose the following diagnostic criteria for the syndrome. The diagnostic criteria for sporadic cases would include a normal karyotype and either (1) a combination of holoprosencephaly and post-axial polydactyly with or without other characteristics, or (2) a combination of holoprosencephaly with other characteristics but without polydactyly, or (3) a combination of postaxial polydactyly, brain defects (microcephaly, hydrocephaly, agenesis of corpus callosum) and other characteristics. The diagnostic criteria for the familial cases would be the same, except that, as long as the other sibs have no abnormalities contradicting the diagnosis, a normal karyotype would be required in only one affected sib.
Lurie
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IW
Department of Pediatrics, School of Medicine, University of Maryland at Baltimore.
Wulfsberg
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EA
D000015:Abnormalities, Multiple / Q000145:classification / Q000235:genetics*; D002869:Chromosome Aberrations / Q000145:classification / Q000235:genetics*; D025063:Chromosome Disorders; D002882:Chromosomes, Human, Pair 13 / Q000648:ultrastructure*; D016142:Holoprosencephaly / Q000235:genetics*; D006801:Humans; D007231:Infant, Newborn; D010641:Phenotype; D017689:Polydactyly / Q000235:genetics*; D013577:Syndrome; D014314:Trisomy