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Holoprosencephaly (HPE) is the most commonly occurring congenital structural forebrain anomaly in humans. HPE is associated with mental retardation and craniofacial malformations. The genetic causes of HPE have recently begun to be identified, and we have previously shown that HPE can be caused by haploinsufficiency for SONIC HEDGEHOG ( SHH). We hypothesize(More)
Deletions of chromosome 18q are among the most common segmental aneusomies compatible with life. The estimated frequency is approximately 1/40,000 live births [Cody JD, Pierce JF, Brkanac Z, Plaetke R, Ghidoni PD, Kaye CI, Leach RJ. 1997. Am. J. Med. Genet. 69:280-286]. Most deletions are terminal encompassing as much as 36 Mb, but interstitial deletions(More)
One of our primary goals is to help families who have a child with an 18q deletion anticipate medical issues in order to optimize their child's medical care. To this end we have narrowed the critical regions for four phenotypic features and determined the penetrance for each of those phenotypes when the critical region for that feature is hemizygous. We(More)
Cobblestone lissencephaly is the characteristic brain malformation observed in Fukuyama congenital muscular dystrophy (FCMD), muscle-eye-brain disease (MEB), and Walker-Warburg syndrome (WWS). The diagnostic criteria for all three require the presence of congenital muscular dystrophy, and criteria for MEB and WWS require retinal abnormalities. We report(More)
Lissencephaly (smooth-brain) is an abnormality of brain development characterized by incomplete neuronal migration and a smooth cerebral surface. At least 2, and possibly more, distinct pathological types occur, each associated with several distinct syndromes. In this paper, the manifestations of 3 disorders associated with type I (classical) lissencephaly(More)
Chromosomal microarray analysis (CMA) by array-based comparative genomic hybridization (CGH) is a new clinical test for the detection of well-characterized genomic disorders caused by chromosomal deletions and duplications that result in gene copy number variation (CNV). This powerful assay detects an abnormality in approximately 7-9% of patients with(More)
Recently, a new clinically recognizable syndrome resulting from a small interstitial deletion of 17p [del(17)(p11.2p11.2)] was described in ten unrelated patients. We have identified six additional patients with similar cytogenetic and phenotypic abnormalities. Consistent clinical manifestations include 1) brachycephaly with a broad face and nasal bridge,(More)
Miller-Dieker syndrome, which includes lissencephaly and a characteristic phenotypic appearance, has been reported to have an autosomal recessive pattern of inheritance. However, we have found abnormalities of chromosome 17 in two of three unrelated patients with this syndrome, one with a ring chromosome 17 and the other with an unbalanced translocation(More)
Most deletions of the long arm of chromosome 18 involve some part of the most distal 30 Mb. We have identified five individuals with cytogenetically diagnosed interstitial deletions that are all proximal to this commonly deleted region. The extent of their deletions was characterized using molecular and molecular cytogenetic techniques. Each participant was(More)
We describe an infant with clinically apparent oto-palatal-digital syndrome Type II (OPD II), who, in addition, also has hydrocephalus and cerebellar hypoplasia. This second X-linked disorder has not been reported previously to occur in association with OPD II. This patient had 2 maternal uncles who died neonatally with congenital hydrocephalus and digital(More)