Hirschsprung disease in an infant with a contiguous gene syndrome of chromosome 13.

Hirschsprung disease is a developmental disorder resulting from the arrest of the craniocaudal migration of enteric neurons from the neural crest along gastrointestinal segments of variable length; see Behrman [Nelson textbook of pediatrics, 1992:954-956]. It is a heterogeneous disorder in which familial cases map to at least three loci whose function is necessary for normal neural crest-derived cell development. Homozygous mutations in the endothelin-B receptor gene (EDNRB) on 13q22 have been identified in humans and mice with Hirschsprung disease type 2 (HSCR2). The auditory pigmentary disorder, Waardenburg-Shah syndrome, comprises Waardenburg syndrome and Hirschsprung disease and has also been mapped to the EDNRB locus. Hirschsprung disease, malrotation, isochromia, a profound sensorineural hearing loss, and several other anomalies were found in an infant with an interstitial deletion of 13q, suggesting the existence of a contiguous gene syndrome involving developmental genes necessary for the normal growth of the neural crest derivatives of the eye, inner ear, and colon. We report on an additional patient with a deletion in 13q and Hirschsprung disease. Congenital anomalies associated with deletions of the distal long arm of chromosome 13 are sufficiently consistent to suggest a clinical syndrome.

Fronto-ocular syndrome: newly recognized trigonocephaly syndrome.

We describe an apparently unique disorder, Fronto-Ocular syndrome, present in a mother and her two daughters, and comprising trigonocephaly due to coronal and metopic craniosynostosis, ocular hypotelorism, ocular proptosis and ptosis, epicanthal folds, hypoplastic supraorbital ridges, elevated nasal bridge, thin philtrum, high-arched palate and a narrow bifrontal region. Both daughters have glabellar capillary hemangiomas, a congenital heart defect and mild developmental disabilities. Review of the literature failed to disclose any syndrome with similar findings. It is likely that this disorder represents an autosomal dominant condition, that arose as a new mutation in the mother. Mutational analysis of fibroblast growth factor receptor (FGFR) 1 and FGFR2 failed to identify the molecular basis of the disorder.

Simultaneous occurrence of two supernumerary autosomal ring chromosomes r(1) and r(16) in twins.

Ring chromosomes are estimated to occur in 3/10000 newborns and the simultaneous occurrence of two autosomal rings must be a very rare event. Recently, the characterisation of these markers using fluorescence in situ hybridisation (FISH) has greatly enhanced cytogenetic-phenotypic correlations in patients with these marker chromosomes. This kind of analysis enabled us to clarify a unique karyotype containing a r(1) and a r(16) in identical twins born after a 26 week gestation with minimal somatic abnormalities. The origin of the rings was identified using a satellite and whole chromosome painting probes. FISH analysis showed the same abnormal female karyotype in both twins, 48,XX,+r(1)(p13q21),+r(16)(p11q11).ish r(1) (D1Z5+,wcpl+), r(16)(D16Z2+,wcp16+) in about two thirds of the cells. Each also had minor clones with a normal female karyotype or with one or the other supernumerary ring. Half of the r(1) contained CBG band negative material and the r(16) appeared to be totally CBG band positive. These twins represent the second report of the simultaneous occurrence of multiple autosomal rings. Their description may help to delineate a new chromosome disorder and shows the usefulness of FISH analysis.

A large Alu-mediated deletion, identified by PCR, as the molecular basis for glycogen storage disease type II (GSDII).

Glycogen storage disease type II (GSDII) is an autosomal recessive disorder resulting from inherited deficiency of the enzyme lysosomal acid alpha-glucosidase. Over 40 different mutations have been described but no large deletions have been previously identified. We now describe a homozygous large (9-kb) deletion extending from IVS 15 to 4 kb downstream of the terminal exon (exon 20), detected by polymerase chain reaction (PCR)-based methods. The deletion was initially suspected because of failure to amplify a contiguous group of exons by PCR. We hypothesized an Alu/Alu recombination, based on our prior demonstration by Southern blotting of Alu elements in the regions potentially flanking the deletion. Additional sequence analysis of genomic fragments confirmed the presence of Alu elements and allowed the design of flanking primers for PCR amplification. Amplification resulted in a smaller than normal fragment (0.7 vs. 10 kb) in homozygosity in the proband and in heterozygosity in her parents. Cloning and sequencing of the smaller than normal 0.7-kb deletion fragment revealed an Alu/Alu deletion junction. In heterozygosity this deletion would not be detected by currently standard PCR mutation detection methods. Based on other Alu-mediated deletions, this deletion is likely to be recurrent and should be screened for in all non-consanguineous GSDII patients, particularly when only one mutation has been identified and none of the 12 single-nucleotide polymorphisms in the deleted region are heterozygous. These observations also suggest that initial characterization of genes at disease-causing loci should include a search for Alu and other repetitive elements to facilitate subsequent PCR-based mutation analysis.

Second-trimester molecular prenatal diagnosis of sporadic Apert syndrome following suspicious ultrasound findings.

Apert syndrome, an autosomal dominant disorder characterized by craniosynostosis, mid-facial malformations, symmetric bony syndactyly of hands and feet, and varying degrees of mental retardation, is most frequently caused by a de novo mutation. Two missense mutations in the fibroblast growth factor receptor 2 (FGFR2) gene have been found to account for the disorder in approximately 98% of affected patients. Seven cases of prenatal ultrasound diagnosis have been reported. Although one earlier diagnosis has been made in a familial case, sporadic cases have not been definitively diagnosed until the third trimester when craniosynostosis is usually detected. We report a second-trimester molecular diagnosis of a sporadic case, based on the ultrasound observation of fetal 'mitten hands' and craniosynostosis. We discuss the approach to such ultrasound features, given the current availability of molecular diagnosis for Apert syndrome.

Further delineation of the Opitz G/BBB syndrome: report of an infant with complex congenital heart disease and bladder exstrophy, and review of the literature.

The combination of complex congenital heart disease (double outlet right ventricle with pulmonary atresia, malalignment ventriculoseptal defect, right-sided aortic arch with left ductus arteriosus) and bladder exstrophy occurred in an infant with Opitz syndrome. Neither of these defects has previously been reported in association with Opitz syndrome. These malformations, which are midline defects, further characterize this syndrome as an impairment in midline development. The spectrum of congenital heart disease and genitourinary anomalies seen in Opitz syndrome is reviewed.

Favorable prognosis for children with Pfeiffer syndrome types 2 and 3: implications for classification.

Pfeiffer syndrome (PS) is an autosomal dominant condition comprising bilateral coronal craniosynostosis, midface hypoplasia with a beaked nasal tip, and broad and medially deviated thumbs and great toes. It is a clinically variable disorder and has been divided into three subtypes [Cohen, 1993: Am J Med Genet 45:300-307]. Type 1 represents the less severe cases, while types 2 and 3 are the more severe cases. These latter types tend to have a higher risk for neurodevelopmental problems and a reduced life expectancy. Here we review the clinical course of seven children with PS type 3. All of these children had severe manifestations of PS; however, development was essentially normal in three, mild delay was noted in two, and moderate delay in one. Favorable outcomes in children with types 2 and 3 PS were also documented by Moore et al. [1995: Cleft Pal-Craniofac J 32:62-70]. These cases illustrate that while children with PS types 2 and 3 have an increased risk for neurodevelopmental difficulties, a favorable outcome can be achieved in some cases with aggressive medical and surgical management. Finally, although such management should be the rule for PS types 2 and 3, it needs to be remembered that normal outcome is not the rule. The prognosis for favorable neurodevelopmental outcome and/or life expectancy remains guarded in most cases.

Opitz G/BBB syndrome, a defect of midline development, is due to mutations in a new RING finger gene on Xp22.

Opitz syndrome (OS) is an inherited disorder characterized by midline defects including hypertelorism, hypospadias, lip-palate-laryngotracheal clefts and imperforate anus. We have identified a new gene on Xp22, MID1 (Midline 1), which is disrupted in an OS patient carrying an X-chromosome inversion and is also mutated in several OS families. MID1 encodes a member of the B-box family of proteins, which contain protein-protein interaction domains, including a RING finger, and are implicated in fundamental processes such as body axis patterning and control of cell proliferation. The association of MID1 with OS suggests an important role for this gene in midline development.

The Marshall syndrome: report of a new family and review of the literature.

The Marshall syndrome is an autosomal dominant trait comprising ocular abnormalities, sensorineural hearing loss, craniofacial anomalies, and anhidrotic ectodermal dysplasia. To our knowledge, only seven additional multigenerational families have been reported since the initial description of the disorder by Marshall in 1958. We present a family in which six members in four generations are affected with apparent Marshall syndrome. We also review and compare similar disorders, such as Stickler, Weissenbacher-Zweimüller, and Wagner syndromes, and conclude that Marshall syndrome is a distinct entity.

Central nervous system anomalies in Seckel syndrome: report of a new family and review of the literature.

Seckel syndrome (SS) is a rare, heterogeneous form of primordial dwarfism. The clinical delineation of this disorder has been inconsistent, using even Seckel's original criteria. As a result, probably fewer than one-third of reported cases are truly affected with SS. Among these, there have been only six familial cases, all of whom were born to normal parents, and in only one case has a detailed description of the central nervous system (CNS) anomalies been given. We describe a family in which three of eight children were affected with SS. CNS anomalies seen in our patients included agenesis of the corpus callosum, a dysgenetic cerebral cortex, a large dorsal cerebral cyst, and pachygyria, suggesting an underlying neuronal migration disorder. The parents are first cousins, representing only the second instance of consanguinity, supporting an autosomal recessive mode of inheritance.

Hemimaxillofacial dysplasia: a report of two new cases and further delineation of the disorder.

Miles, Lovas, and Cohen first described hemimaxillofacial dysplasia in two patients in 1987. This disorder consists of facial asymmetry, facial hypertrichosis, unilateral maxillary hyperplasia, and hypoplastic teeth. We report two additional cases with similar findings.

Prenatal diagnosis of type 2 Pfeiffer syndrome.

Pfeiffer syndrome is an autosomal dominantly inherited disorder consisting of craniosynostosis, a flattened midface with a beaked nose and ocular proptosis, and broad and medially deviated thumbs and great toes. Recently, based on clinical findings, the disorder has been divided into three subtypes: type 1, characterized by mild expression; type 2, in which clover leaf skull deformity and multiple congenital anomalies are present at birth; and type 3, which is similar to type 2, but lacks the presence of the clover leaf skull at birth. We describe a fetus in whom sonographic findings of clover leaf skull deformity, ocular hypertelorism, and varus deformity of the great toe led to the prenatal diagnosis of Pfeiffer syndrome type 2. We believe this is the second prenatal diagnosis of Pfeiffer syndrome, and the first time type 2 has been definitely identified in the second trimester of pregnancy.

"C" trigonocephaly syndrome: report of a child with agenesis of the corpus callosum and tetralogy of Fallot, and review.

We report on a new case of the Opitz "C" trigonocephaly syndrome. Our patient had agenesis of the corpus callosum, an anomaly seen only twice previously, and tetralogy of Fallot, described only once before. A review shows that a combination of conotruncal heart defects and midline brain anomalies characterizes patients with this entity.