Linkage exclusion and mutational analysis of the noggin gene in patients with fibrodysplasia ossificans progressiva (FOP)

Fibrodysplasia ossificans progressiva (FOP) is an extremely rare and disabling genetic disorder characterized by congenital malformation of the great toes and by progressive heterotopic endochondral ossification in predictable anatomical patterns. Although elevated levels of bone morphogenetic protein 4 (BMP4) occur in lymphoblastoid cells and in lesional cells of patients with FOP, mutations have not been identified in the BMP4 gene, suggesting that the mutation in FOP may reside in a BMP4-interacting factor or in another component of the BMP4 pathway. A powerful antagonist of BMP4 is the secreted polypeptide noggin. A recent case report described a heterozygous 42-bp deletion in the protein-coding region of the noggin gene in a patient with FOP. In order to determine if noggin mutations are a widespread finding in FOP, we examined 31 families with 1 or more FOP patients. Linkage analysis with an array of highly polymorphic microsatellite markers closely linked to the noggin gene was performed in four classically-affected multigenerational FOP families and excluded linkage of the noggin locus to FOP (the multipoint lod score was -2 or less throughout the entire range of markers). We sequenced the noggin gene in affected members of all four families, as well as in 18 patients with sporadic FOP, and failed to detect any mutations. Single-strand conformation polymorphism (SSCP) analysis of 4 of these patients plus an additional 9 patients also failed to reveal any mutations. Among the samples analyzed by SSCP and DNA sequencing was an independently obtained DNA sample from the identical FOP patient previously described with the 42-bp noggin deletion; no mutation was detected. Examination of the DNA sequences of 20 cloned noggin PCR products, undertaken to evaluate the possibility of a somatic mutation in the noggin gene which could be carried by a small subset of white blood cells, also failed to detect the presence of the reported 42-bp deletion. We conclude that mutations in the coding region of noggin are not associated with FOP.     

Increase in ferric and ferrous iron in the rat hippocampus with time after kainate-induced excitotoxic injury

The present study aimed to elucidate the distribution of ferric and ferrous iron in the hippocampus after kainate-induced neuronal injury. A modified Perl's or Turnbull's blue histochemical stain was used to demonstrate Fe3+ and Fe2+ respectively. Very light staining for iron was observed in the hippocampus, in normal or saline-injected rats and 1-day post-kainate-injected rats. At 1 week postinjection, a number of Fe3+-positive, but very few Fe2+-positive, cells were present, in the degenerating CA fields. At 1 month postinjection, large numbers of Fe3+-positive glial cells, and some Fe2+-positive blood vessels, were observed. At 2 months postinjection, large numbers of Fe3+- and Fe2+-positive glial cells were present. The labeled cells had light and electron microscopic features of oligodendrocytes, and were double labeled with CNPase, a marker for oligodendrocytes. The observation of an increasing number of Fe3+- and Fe2+-positive cells in the degenerating hippocampus with time is consistent with the results of a nuclear microscopic study, in which an increasing amount of iron was detected in the degenerating hippocampus after kainate injection. In addition, the present study showed a shift in the oxidation state of the accumulated iron, with more cells becoming Fe2+ at a late stage. A possible consequence of the high amounts of Fe2+ in the hippocampus after kainate injection is that it could promote free radical damage in the lesioned areas.     

Detection of a 15q deletion in a child with Angelman syndrome by cytogenetic analysis and flow cytometry

A proximal 15q deletion, del(15) (q11:q13), was detected in a child with Angelman syndrome by cytogenetic analysis of peripheral lymphocytes. The chromosomes of both parents appeared normal. Flow karyotype analysis carried out on lymphoblastoid cell lines derived from the child and her parents confirmed the presence of a de novo 15 deletion. The estimated size of the deleted segment ranged from 6.1-9.5% of chromosome 15 (approximately 6-9.3 million base pairs). The parental origin of the deleted chromosome could not be resolved by flow cytometry, but cytogenetic evidence suggested that it was derived from the smaller chromosome 15 homologue in the mother.     

A light and electron microscopic study of the iron transporter protein DMT-1 in the monkey cerebral neocortex and hippocampus

We have studied by immunocytochemistry, the distribution of DMT-1, a cellular iron transporter responsible for transport of metal irons from the plasma membrane to endosomes, in the normal monkey cerebral neocortex and hippocampus. Light to moderate DMT-1 staining was observed in glial cell bodies in the neocortex, the subcortical white matter, and the hippocampus. Despite light labeling of cell bodies, glial end feet around cortical and subcortical blood vessels were heavily labeled. In the neocortex, the glial cell bodies displayed the morphological features of protoplasmic astrocytes. Labeled glial cells in the subcortical white matter contained dense bundles of glial filaments and were identified as fibrous astrocytes. The observation that DMT-1 was present on astrocytic endfeet suggests that these cells are involved in uptake of iron from endothelial cells. It is possible that the iron could then be redistributed into the extracellular space in the brain parenchyma.     

A three generation family with fibrodysplasia ossificans progressiva.

A family with five persons affected with fibrodysplasia ossificans progressiva (myositis ossificans progressiva) in three generations is described. This is the first well documented three generation family with this condition and provides further evidence for autosomal dominant inheritance. A wide range of phenotypic severity is apparent, from disabling ectopic bone formation and premature death to an asymptomatic adult with characteristic big toe malformations.     

Prediction of liability to orofacial clefting using genetic and craniofacial data from parents.

BACKGROUND: Cleft lip with or without cleft palate (CL(P)) and isolated cleft palate (CP) are separate clinical entities and for both polygenic multifactorial aetiology has been proposed. Parents of children with orofacial clefting have been shown to have distinctive differences in their facial shape when compared to matched controls. OBJECTIVE: To test the hypothesis that genetic and morphometric factors predispose to orofacial clefting and that these markers differ for CL(P) and CP. Methods-Polymorphisms at the transforming growth factor alpha (TGFalpha) locus in 83 parents of children with nonsyndromic orofacial clefts were analysed, and their craniofacial morphology was assessed using lateral cephalometry. RESULTS: Parents of children with CL(P) and CP showed an increased frequency of the TGFalpha/TaqI C2 allele (RR=4.10, p=0.009) relative to the comparison group. Also the TGFalpha/BamHI A1 allele was more prevalent in the CP parents. MULTIVARIATE STATISTICAL ANALYSIS: Using stepwise logistic regression analysis the TGFalpha/TaqI C2 polymorphism provides the best model for liability to orofacial clefting. To determine the type of clefting a model involving interaction between the parental TGFalpha/BamHI and TGFalpha/RsaI genotypes showed the best fit. Using genotype only to predict the clefting defect in the children according to parental genotype, 68.3% could be correctly classified. By adding information on craniofacial measurements in the parents, 76% of CP and 94% of CL(P) parents could be correctly classified. CONCLUSIONS: This study provides a model for prediction of liability to orofacial clefting. These findings suggest that different molecular aberrations at the TGFalpha locus may modify the risk for CP and CL(P).     

Guinea pig cytomegalovirus: Transplacental transmission

Summary A well characterized strain of guinea pig cytomegalovirus (GPCMV) was used to infect pregnant guinea pigs during various periods of pregnancy. Transplacental transmission of virus with invasion of the fetus was observed, even in some mothers with preinoculation evidence of GPCMV antibody. Fetal infection occurred during the middle third of pregnancy and GPCMV was isolated from many fetal tissues although histologic evidence of infection was not noted. During the last third, abortion of the pregnancy occurred in some animals.This report demonstrates that GPCMV may invade the fetus producing a sublethal, possibly mild infection which may be very similar to the usual type of CMV infection observed in the human newborn.     

Promoting dietary change: demonstrating reduction of dietary fat

This short demonstration accomplishes several goals. People see where fat comes from and learn amounts needed to be removed. They practice substituting complex carbohydrate foods for fat. Most important, they learn that changing is not an "all-or-nothing" proposition. They can reduce dietary fat and still eat many of their favorite foods. This demonstration is a useful tool for nutrition educators who want to promote dietary change.     

Loiasis: "Calabar" swellings and involvement of deep organs

The authors report clinical and histopathologic changes in six patients with symptomatic loiasis. One patient had cutaneous swellings, three patients presented with hydrocele, one patient developed bowel obstruction, and one had generalized fatal loiasis. The first five patients had localized lesions provoked by adult worms; all were surgically removed. The sixth patient died of disseminated loiasis that included a severe loal encephalitis. The authors discuss the mechanism of "Calabar" swellings, the reaction to adult Loa loa worms and loal encephalitis.