Holoprosencephaly and Klinefelter Syndrome

Holoprosencephaly (hpe) is a malformation that arises during the first 4 weeks of embryonic development (blastogenesis) caused by a failure or incomplete division of the prosencephalon into cerebral hemispheres. this defect is frequently associated with other facial anomalies such as anophthalmia, cyclopia, proboscis, midface clefting, hypertelorism, single maxillary central incisor, and absence of olfactory nerves or corpus callosum. it is a causally heterogeneous field defect caused by: 1) chromosome aberrations in particular trisomy 13, partial deletion of the long arm of the chromosome7, triploidy (69, xxy) and other recessive, dominant,or x-linked genes multifactorial causes. klinefelter syndrome is the most common sex chromosome abnormality in men and boys, with a reported prevalence of 0.1% to 0.2% in the general population and of up to 3.1% in the infertile male population.