Duplication 8 [inv dup(8)(p12p23)] with macrocephaly.

A 10-month old female is described with inv dup(8)(p12p23) who had macrocephaly with subtle changes in facial appearance and no structural birth defects. Her findings, together with those of 37 reported cases with inv dup (8), define a syndrome that emphasizes the importance of genes on the 8p region for brain development.

Novel assay for Roberts syndrome assigns variable phenotypes to one complementation group.

Roberts syndrome (RS) is a rare autosomal recessive disorder characterized by heterogeneous clinical features, the most notable being tetraphocomelia, cleft lip, and cleft palate. Cells derived from most RS patients exhibit abnormal cytogenetic and cellular phenotypes that include the premature separation of para- and pericentromeric heterochromatin visible on C-banded metaphase chromosomes, a phenomenon referred to as heterochromatic splaying. Previously, it was shown that these abnormal phenotypes can be complemented following somatic cell hybridization between RS cells and control cells. In the current study, a permanent cell line was established from a new RS patient with a more severe phenotype than represented by previously established cells in culture. With a newly developed assay designed to facilitate rapid evaluation of in vitro complementation, we assigned this new patient to the same genetic complementation group defined by other, less severely affected patients. The results demonstrate that a single complementation group defines RS patients with heterochromatic splaying regardless of clinical severity.

Down syndrome: perinatal complications and counseling experiences in 216 patients.

Two hundred and sixteen infant evaluations were selected for analysis from those of 669 outpatients (930 total visits) at a weekly Down syndrome clinic. Each record contained perinatal history and physical examination results, and 191 of the 216 included a systematic interview regarding parental experiences with diagnosis and counseling. Gastrointestinal problems (77% of neonates), cardiac anomalies (38%), and hematologic problems (11%) were the most common complications; cited problems included anal stenosis (11%), which is described as a newly recognized cause of constipation in early infancy. Counseling experiences were positive in 66 (34%) of the 191 parent interviews, with counselor knowledge, timing, setting, and attitudes being cited as key factors. Appropriate counseling and surveillance for gastrointestinal problems can greatly facilitate parental adjustment to the neonate with Down syndrome.

Thirteen cases of Niikawa-Kuroki syndrome: report and review with emphasis on medical complications and preventive management.

Eight new and five previously illustrated patients with Niikawa-Kuroki syndrome (NKS) are compared to those in the literature, providing data on 183 cases. Eight patients had disproportionate microcephaly and in one autopsied patient there was frontal lobe atrophy, focal polymicrogyria, and a hypoplastic fourth ventricle. The metacarpophalangeal pattern profiles of three Caucasian patients with NKS were similar to that of a prior case report, but those of two Hispanic patients were more variable. NKS was eliminated by follow-up in nine suspect cases, highlighting the diagnostic value of findings such as arched eyebrows, long palpebral fissures, flat nasal tip, and prominent finger pads. One patient suspected of having NKS had a very different metacarpophalangeal pattern profile, supporting its diagnostic utility in selected cases. Higher frequencies of neonatal complications, abnormal dentition, hypotonia, and microcephaly were noted in non-Asian patients with NKS, while a higher frequency of skeletal anomalies was seen in Japanese patients. Complications affecting cognitive, visual, hearing, cardiac, renal, skeletal, immune, and endocrinologic functions are translated into a program for preventive management. X chromosome anomalies are the most compelling of diverse genetic changes seen in NKS, and this report adds another case to several possible instances of vertical transmission. The 108 non-Asian patients now reported emphasize the worldwide significance of NKS recognition.

Correlated heart/limb anomalies in Mendelian syndromes provide evidence for a cardiomelic developmental field.

Coordinated development of heart and limbs is suggested by a review of human abortus, chromosomal, and teratogenic syndromes, and characterized by an analysis of Mendelian disorders that affect the limbs, heart, or both (672, 202, or 107, respectively). Mendelian syndromes with altered limb patterns often include cardiac anomalies, as shown by limb duplications (34%), deficiencies (30%), hypoplasias (23%), or dysplasias (9.3%). Syndromes with particular cardiac anomalies, illustrated by VSD (85%) or ASD (90%), frequently include limb defects. Positional correlations of anterior (preaxial/conotruncal), posterior (postaxial/atrial), or lateral (mirror hand/atrial isometry) heart/limb anomalies are consistent with the existence of a cardiomelic developmental field. Vertebrate comparisons suggest an early D-V limb-heart gradient, influenced by the neural crest, with distal limb segments (80% of syndromic defects) at its dorsal extreme. The proposed cardiomelic field relates the genetic heterogeneity of disorders such as Holt-Oram syndrome to a cascade of molecules, including the brachyury, sonic hedgehog, bone morphogenetic protein, retinoic acid receptor, and transforming growth factor-beta families.

Robertsonian (15q;15q) translocation in a child with Angelman syndrome: evidence of uniparental disomy.

A balanced Robertsonian translocation 45,XY,t(15q15q) was detected in a patient with mental retardation, microcephaly, and hypertonia. Deletion of the 15q11q13 region was unlikely based on fluorescence in situ hybridization studies that revealed hybridization of appropriate DNA probes to both arms of the Robertsonian chromosome. Inheritance of alleles from 13 highly polymorphic DNA markers on chromosome 15 showed paternal uniparental isodisomy. The clinical, cytogenetic, and molecular results are consistent with a diagnosis of Angelman syndrome.

Is there a cocaine syndrome? Dysmorphic and anthropometric assessment of infants exposed to cocaine.

It was suggested that a "fetal cocaine syndrome" exists. The objective of this study was to systematically investigate whether or not a "cocaine syndrome" exists. The setting was Parkland Memorial Hospital, a large urban public hospital in Dallas, TX, where approximately 15,000 infants are delivered annually. Infants who tested positive by urinalysis for cocaine (n = 25) were included in this study. Controls negative for cocaine (n = 25) were matched to cocaine-exposed infants for estimated gestational age, sex, and race. A standardized dysmorphology examination (135 features) and a series of anthropometric measures (n = 22) were done for each cocaine-exposed and control infant by an observer blinded to drug-exposure status. Fetal growth retardation characterized cocaine-exposed infants. No characteristic pattern of minor dysmorphic or anthropometric features of the face, limbs, or torso was observed among cocaine-exposed infants. Cocaine-exposed infants lack a facial gestalt or torso/limb features that would characterize a syndrome. If a "cocaine syndrome" that can be characterized dysmorphologically and/or anthropometrically exists, its occurrence seems infrequent.

A model for human situs determination.

Alterations of human laterality range from situs reversal or consensus isometry to isolated anomalies of the cardiac, respiratory, gastrointestinal, skeletal, and central nervous systems. A mechanism for human situs determination has been derived from the general model of Brown and Wolpert (1990) , with steps involving A-P axis, D-V axis, midline, global situs, and local situs specification. Comparison with Drosophila segmentation is supported by maternal transmission of certain human situs defects and mutation of appropriate Drosophila gene homologues in the human Waardenburg and Greig syndromes. Anteroposterior gradients in expression of vertebrate homeotic genes may relate to a proposed hierarchy of regional laterality decisions. Early alterations in A-P or D-V axis polarity would produce situs reversal in 100 of individuals, as observed in pure situs inversus, homozygous inv mice or manipulated Xenopus embryos. Later alterations would permit random right-left decisions and account for heterotaxy in 50 of affected individuals, as observed in poly asplenia or homozygous iv mice. Randomisation of brain asymmetry could explain why situs but not brain laterality may be reversed in humans, with forebrain situs reversal or isometry leading to brain anomalies. Homologues of Drosophila genes regulating axis polarity, heart and gut development are attractive candidates in human laterality disorders, but none is uniquely localised to the 6q14-q21 or9q32-q34, 7q22, 10q21-22, 11q13 or 11q25, 12q13, 13qter, or Xq24-q27.1 chromosome regions highlighted by heterotaxic patients or mutant mice.

Differential evolution and expression of murine peroxisomal membrane protein genes.

Gene segments encoding the 70 and 22-kDa peroxisomal membrane proteins (PMP) have been characterized in mice and compared with other peroxisomal proteins in terms of evolution and expression. The mouse PMP22 gene sequence predicts A16G and I136V substitutions that agree with those defined by cyanogen bromide cleavage analysis, providing additional evidence that this gene encodes the major 22-kDa membrane protein visualized by SDS-polyacrylamide electrophoresis. Mammalian PMP22 genes exhibit high evolutionary rates (0.17% amino acid substitution per million years) than PMP35 (0.14%), PMP70 (0.07%), or catalase genes (0.13%). PMP70 gene regions are conserved throughout vertebrate phylas based on Southern analysis, while PMP22 sequences were only detected in rodents. Amino acid substitutions are clustered in both PMP22 and PMP70 genes, and their pattern supports membrane topologies derived from hydropathy profiles. Northern blot analysis identifies single mRNAs of 4.6 kb (PMP70), 1.4 kb (PMP22), and 2.3 kb (catalase) in several rodent tissues. Quantitative or competitive RT-PCR assays detected two- to three-fold greater numbers of catalase mRNA molecules relative to PMP mRNA molecules in brain, liver, and kidney; PMP22 and PMP35 mRNAs were two-fold more abundant than PMP70 mRNA in these tissues. Steady-state levels of PMP22 mRNA were highest in rodent liver kidney, spinal cord, and duodenum with low levels in colon, adrenal, thymus, and spleen. We conclude that PMP genes exhibit independent evolutionary rates and tissue regulation, suggesting that they have unique roles in peroxisome biogenesis and tissue differentiation.

Interstitial deletions 4q21.1q25 and 4q25q27: phenotypic variability and relation to Rieger anomaly.

We describe clinical and chromosomal findings in two patients with del(4q). Patient 1, with interstitial deletion (4)(q21.1q25), had craniofacial and skeletal anomalies and died at 8 months of hydrocephalus. Patient 2, with interstitial deletion (4)(q25q27), had craniofacial and skeletal anomalies with congenital hypotonia and developmental delay. These patients shared certain manifestations with other del(4q) patients but did not have Rieger anomaly. Clinical variability among patients with interstitial deletions of 4q may be related to variable expression, variable deletion, or imprinting of genes within the 4q region.

Atypical inheritance: new horizons for neurology.

Rediscovery of Mendel's laws produced an enthusiastic new discipline at the turn of this century. The eugenics movement had many disciples in the United States, and it should be noted that the term "final solution" was first used by the National Association of Charities and Corrections in the 1920s. American advocates of eugenics accomplished mass sterilization of retarded individuals and the prohibition of Jewish immigration from Germany during World War II. It is interesting that the close of this century has produced a similar revolution in genetics. These newer genetic mechanisms expose the major fallacy of eugenics: traits may be genetic without showing obvious familial transmission. Sanctions against reproduction or immigration thus will have little effect on the gene pool. The clinical implications of atypical inheritance are enormous. Almost every medical disorder must be reinvestigated for evidence of subtle chromosome changes, for worsening in progressive generations, and for influence of parental origin. The classical Mendelian model taught that extreme and rare phenotypes shed light on more frequent ones, hence the definition of genes responsible for hypercholesterolemia, for Alzheimer disease, and for amyotrophic lateral sclerosis. Atypical inheritance mechanisms further enhance this approach, bringing all of neurology under the light of genetic technology. The lure for the practitioner, then, is not the hyperbole of molecular biology; it is the need for a seasoned hand so emphasized by Huntington's disease and the duty to protect the next century from disasters of the current one.

Structure and expression of mammalian peroxisome assembly factor-1 (PMP35) genes.

Mammalian genes encoding a 35-kDa peroxisomal membrane protein (PMP35, peroxisome assembly factor-1) are compared using the polymerase chain reaction and DNA sequencing. DNA sequencing of the 915 bp of the PMP35 coding regions was in complete agreement with previously published rat data and showed 36 and 133 nucleotide substitutions, respectively, in mouse and man. The 12 and 35 respective amino acid changes encoded by these nucleotide substitutions are clustered and compatible with putative membrane-spanning regions. Rat/human and rat/mouse comparisons yield silent mutation rates of 0.33 and 0.21% per site per million years and replacement mutation rates of 0.082 and 0.076%; transitions account for 67% (human/mouse) and 83% (rat/mouse) of nucleotide replacements among PMP35 genes. PMP35 gene expression in mouse tissues as measured by reverse transcriptase-PCR was responsive to clofibrate and disproportionately high in neural tissue.

Multiple coagulation defects and the Cohen syndrome.

A 13-year-old male presented with new onset seizures, sagittal sinus thrombosis with cerebral hemorrhage, and extensive venous thrombosis of the lower limbs. Laboratory investigation demonstrated combined deficiency of protein C, protein S, and antithrombin III. He and his 17-year-old sister had a mental retardation-multiple anomaly syndrome associated with microcephaly, unusual facies, and lax connective tissue. Their dysmorphology included elongated faces with narrow forehead, arched eyebrows, large mouth with down-turned corners, malformed teeth, and furrowed tongue. Both had Marfanoid habitus with lax joints, pectus excavatum, kyphoscoliosis, and flat narrow feet. The most likely diagnosis for these siblings is the autosomal recessive Cohen syndrome of mental retardation, congenital hypotonia with Marfanoid habitus, microcephaly, pleasant affect, micrognathia, and open mouth with prominent incisors. The sagittal sinus thrombosis, left frontal intracranial hemorrhage, carotid aneurysm, tortuous descending aorta, and deep venous thrombosis suffered by the male sibling adds the Cohen syndrome to genetic vasculopathies that may be associated with stroke.

Three cases of dup(10p)/del(10q) syndrome resulting from maternal pericentric inversion.

Two families and 3 patients with dup(10p)/del(10q) syndrome segregating from a maternal pericentric inversion are described, including a stillborn female with Potter sequence and multicystic renal dysplasia. Comparison of 32 dup(10p) patients to 11 del(10)(q25) patients emphasized dolichocephaly, wide sutures, frontal bossing, micrognathia, and renal defects as distinguishing characteristics of the dup(10p) syndrome. The 3 new and 6 previously reported dup(10p)/del(10q) patients had several manifestations in common with the dup(10p) and del(10q) syndromes, but were more typical of dup(10p) syndrome with respect to all 5 distinguishing characters.

Genomic imprinting: summary of an NICHD conference.

Compelling evidence for genomic imprinting as a pathogenetic mechanism in humans mandates re-evaluation of every genetic or multifactorial disease for parent-of-origin effects. In an expanding list of malformation syndromes, cancers, growth abnormalities, and chromosomal disorders, phenotypes may be determined by source rather than content of transmitted DNA. A multidisciplinary conference held on April 13-14, 1992, reviewed the substantial impact of genomic imprinting in mouse development and discussed in role in human pregnancy, childhood cancers, chromosomal translocations, X-inactivation, and several disorders associated with mental retardation. Topics for future research include the mechanism, timing, reversibility, and homology of the imprinting process.

Index finger hyperphalangy and multiple anomalies: Catel-Manzke syndrome?

We describe a boy with short stature, developmental delay, unusual face, right iris coloboma, malformed ears, micrognathia, and skeletal anomalies including hyperphalangy of the index fingers, bilateral fifth finger clinodactyly, short halluces, and scoliosis. Internal anomalies included asymmetric and dilated cerebral ventricles and ventricular septal defect. The neonatal history of small jaw with feeding and respiratory difficulties suggested a Pierre Robin sequence, but there was no cleft palate. Two maternal uncles with similar anomalies had died at ages 13 months and 5 years, respectively. RFLP studies with the DNA probes DXS72 and F8C were consistent with but not diagnostic of X-linked recessive inheritance. The pattern of anomalies was compatible with a diagnosis of Catel-Manzke syndrome, but a novel dysostosis syndrome must also be considered.