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Biomedical subjects

F C Fraser

Publications and source records attributed to F C Fraser.

At least 37 records · Page 2Linked to original sources
PubMed1995

Nutritional patterns of mothers of children with neural tube defects in Newfoundland.

In an exploratory study of the genetic epidemiology of neural tube defects in Newfoundland, we studied mothers who had given birth to a child with a neural tube defect (NTD) with respect to their nutrition, as well as various other factors. The frequency of NTD in the area studied was 3.5/1,000 births and has not decreased recently, as it has in some other parts of the world. Twenty-five mothers of children with NTD and a comparison group (CG), matched for age and neighbourhood, completed 3 day dietary records. The NTD group consisted of all mothers who had given birth to an NTD child within the previous 3.5 years in the chosen area. The CG mothers were ascertained through the local public health nurse who chose the nearest unaffected child born in the same time period as the NTD probands. NTD mothers were younger, heavier, and of lower socioeconomic status than were CG mothers. CG group women consumed more vitamin supplements during the periconceptional period (P < 0.05) and consumed more dairy and cereal products, fruits and vegetables (other than potatoes), and fewer sweets than did NTD mothers. Sixty-four percent of NTD mothers had folacin intakes below the recommended level (168 mg) compared to 27% of CG mothers (P < 0.01). These findings support previous evidence that poor maternal nutrition, and low dietary folate in particular, increase the chance of having a child with an NTD, and emphasize the need for supplementary folate in the diet of women of childbearing age in areas where the frequency of NTDs is high.

Adult↗
PubMed1995

Teratogenic potential of corticosteroids in humans.

The literature was surveyed in an attempt to assess whether corticosteroids have a detectable teratogenic effect. Reporting bias was illustrated by the fact that the frequency of malformations in offspring of women treated with corticosteroids was much higher in reports of single cases than in reports of series of cases. In the latter group there were 468 exposed women, and the frequency of malformations was 3.5%, no different from the usual population frequency. There were, however, 2 cases of cleft palate, whereas 0.2 cases would be expected; it is impossible to tell whether this is a real increase. We conclude that the teratogenic potential of corticosteroids is so low as to be undetectable from the data available.

Abnormalities, Drug-Induced↗
PubMed1995

Familial hypertryptophanemia in two siblings.

Mild and moderate mental retardation with exaggerated affective responses, periodic mood swings, and apparent hypersexual behavior were present in two siblings with hypertryptophanemia and tryptophanuria. In addition, the male had severe myopia, a speech impediment, musculoskeletal abnormalities and perceptual hypersensitivity. His sister was deaf, which was ascribed to antenatal rubella. The occurrence in siblings and the presence of abnormal urinary tryptophan metabolite in the mother and a half-sibling suggest that the condition results from an autosomal recessive gene with minor expression in some heterozygotes.

Adult↗
PubMed1994

A familial association between twinning and upper-neural tube defects.

An increased twinning rate has been observed in the near relatives (sibs, parents, and aunts and uncles) of probands with neural tube defects (NTDs) occurring at the level of the 11th thoracic vertebra and above (upper NTDs). The twin rate was more than double that of the near relatives of probands with lower NTDs and of those of probands with Mendelian disorders (the controls). The excess twinning was same sex and can therefore consist of either MZ or same-sex DZ twins. Furthermore, upper-NTD families with twins had a higher NTD-sibling occurrence rate than did families without twins. These findings, if corroborated, may imply an etiology common to twinning and NTDs and can perhaps be applied in counseling NTD families.

Female↗
PubMed1993

Recommendations on the use of folic acid supplementation to prevent the recurrence of neural tube defects. Clinical Teratology Committee, Canadian College of Medical Geneticists.

OBJECTIVE: To prevent the recurrence of neural tube defects (NTDs) in families at increased risk of having offspring with NTDs with the use of periconceptional folic acid supplementation. OPTIONS: Genetic counselling and prenatal diagnosis of NTDs. OUTCOMES: NTDs cause stillbirth, neonatal death and severe disabilities. The cost for medical care and rehabilitation in the first 10 years of life of a child with spina bifida cystica was estimated to be $42,507 in 1987. EVIDENCE: The authors reviewed the medical literature, communicated with investigators from key studies, reviewed policy recommendations from other organizations and drew on their own expertise. A recent multicentre randomized controlled trial showed that among women at high risk of having a child with an NTD those who received 4 mg/d of folic acid had 72% fewer cases of NTD-affected offspring than nonsupplemented women. Two previous intervention studies also demonstrated that folic acid supplementation was effective in reducing the rate of NTD recurrence. Several retrospective studies support this conclusion. VALUES: Recommendations are the consensus of the Clinical Teratology Committee of the Canadian College of Medical Geneticists (CCMG) and have been approved by the CCMG Board. The committee believes that primary prevention of NTDs is preferable to treatment or to prenatal detection and abortion. BENEFITS, HARMS AND COSTS: Folic acid supplementation should result in fewer NTDs among infants in Canada and ancillary savings in medical costs. The recommended dosage of folic acid is not known to be associated with adverse effects. Higher dosages of folic acid may make vitamin B12 deficiency difficult to diagnose and may alter seizure frequency in patients with epilepsy due to drug interactions with anticonvulsants. RECOMMENDATIONS: A minimum dosage of folic acid of 0.8 mg/d, not to exceed 5.0 mg/d, is recommended along with a well-balanced, nutritious diet for all women who are at increased risk of having offspring with NTDs and who are planning a pregnancy or may become pregnant. Supplementation should begin before conception and continue for at least 10 to 12 weeks of pregnancy. VALIDATION: These guidelines are similar to those of the Society of Obstetricians and Gynaecologists of Canada, the US Centers for Disease Control and Prevention and the Department of Health in Britain. SPONSORS: These guidelines were developed by the CCMG Clinical Teratology Committee and endorsed by the Board of the CCMG. No funding for the development of these guidelines was obtained from any other sources.

Female↗
PubMed1993

Upper and lower neural tube defects: an alternate hypothesis.

It has been suggested that neural tube defects (NTDs) of the upper type (anencephaly, encephalocele, and thoracic spina bifida) may have a pathogenesis different from those of the lower type (lumbosacral spina bifida), since recurrent cases within a sibship were said always to be concordant with respect to NTD type. Also, spontaneous abortion, additional malformation, and recurrence rate were observed to be higher in the upper group, and there was an excess of females in upper NTD probands. To test this hypothesis, we measured the above variables in upper and lower NTDs in a sample from Quebec. We found less than full concordance (50%) of NTD type in 18 sib pairs. Recurrence rate was not significantly lower in the lower NTD group (5.6 v 5.8%). The other variables were in general agreement with previous studies, inconsistent findings possibly attributable to different NTD population incidences. These findings can be accounted for if upper and lower NTDs share a similar pathogenesis and the embryo is more susceptible during early than late neural tube formation.

Anencephaly↗
PubMed1990

Aminopterin-like syndrome sine aminopterin associated with translocation involving chromosomes 5 and 10.

We studied a baby born with physical features suggestive of the aminopterin syndrome, but without exposure of the mother to aminopterin during pregnancy. G-banded chromosomes from peripheral blood lymphocytes had a normal 46,XX pattern. However, in 50 skin fibroblasts there was a normal female karyotype in 5 cells and 45 cells showed an apparently balanced reciprocal translocation involving the long arm of chromosome 5 (band q35) and the long arm of chromosome 10 (band q22). The relation of this mosaicism to the abnormal phenotype is unclear.

Abnormalities, Multiple↗
PubMed1990

Association between Alzheimer disease and amyotrophic lateral sclerosis?

We report two cases of Alzheimer disease (AD)--one of them familial--in which the patient also had amyotrophic lateral sclerosis (ALS), and one patient with familial AD who had a son with ALS. Three further cases of probable ALS were found in pedigrees of AD reported from the literature. It is proposed that this association is not coincidental, but may suggest an etiological factor in common.

Aged↗
PubMed1990

Recurrence risks for near relatives of children with sensori-neural deafness.

In a sample of children with sensori-neural deafness and no evidence of a syndrome, ototoxic exposure, or autosomal dominant or X-linked family history, seen in the Division of Medical Genetics of The Montreal Children's Hospital, the probability of a sibling being similarly affected was about 1 in 6, both in French-Canadian families and the remainder of the sample. The frequency of deafness of early onset was measured in the uncles and aunts of probands, and these figures were used to derive approximate recurrence risks for the offspring of probands (about 1 in 130, ignoring the possibility of autosomal dominant mutation) and for the offspring of the probands' unaffected sibs (about 1 in 250). A rough estimate of the number of autosomal recessive loci contributing to sensori-neural deafness is derived as 13.

Child↗
PubMed1989

Pectoralis major defect and Poland sequence in second cousins: extension of the Poland sequence spectrum.

We report on a patient with congenital absence of the left pectoralis major muscle, whose second cousin had the full Poland sequence. This suggests that isolated pectoralis major muscle defect should be included in the spectrum of anomalies characterized as the Poland sequence, postulated to result from disruption of blood supply in the embryonic subclavian and vertebral arteries, the site and degree of obstruction determining the sites and severity of the resulting anomalies. Very few cases are familial; in these the family pattern is compatible with an autosomal dominant mutant gene with reduced penetrance or delayed mutation.

Humans↗