Genetic variation in an urban population of Aedes aegypti (Diptera: Culicidae).
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Aedes↗
Biomedical subjects
R E Ferrell
Publications and source records attributed to R E Ferrell.
A syndrome of microcephaly and retinal pigmentary abnormalities without mental retardation in a family with coincidental autosomal dominant hyperreflexia.
We describe two brothers with severe microcephaly, unusual retinal pigmentary anomalies, intellectual function in the average or low average range, and a strong family history of hyperreflexia. The brothers have a previously undescribed syndrome, while the hyperreflexia appears to represent a coincidental autosomal dominant Mendelian trait, perhaps linked to the Kell blood group system.
Abnormalities, Multiple↗
Erythrocyte phosphoglucomutase: a family study of a PGM1 deficient allele.
We have observed a large Mexican American family segregating for a low activity allele at the phosphoglucomutase-1 locus. The deficient allele is detectable by starch gel electrophoresis and by direct activity determination. The presence of the deficient allele in either the homozygous or heterozygous condition is not associated with any other phenotypic finding.
Alleles↗
A general method for visualizing enzymes releasing adenosine or adenosine-5'-monophosphate.
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Adenosine↗
X-linked, polymorphic genetic variation of thyroxin-binding globulin (TBG) in baboons and screening of additional primates.
X-linked polymorphic variation of thyroxin-binding globulin (TBG) is observed in several human groups. Isoelectric focusing of plasma samples labeled in vitro with [125I]thyroxin, followed by autoradiography, also reveals genetically determined polymorphic electrophoretic variation in baboon TBG. The protein detected by this method in baboon plasma is immunologically similar to human TBG and is distinct from the other thyroxin-binding proteins, albumin and prealbumin. The isoelectric patterns of human and baboon TBG are very similar and both have an isoelectric range of pH 4.1 to 4.5. The baboon TBG polymorphism is inherited in a two-allele X-linked fashion, with a frequency of 72% for the "common" allele and 28% for the "slow" allele. A survey of seven other primate species including African green monkey, bonnet macaque, chimpanzee, crab-eating macaque, gorilla, rhesus monkey, and spider monkey revealed no polymorphic variation in TBG, although isoelectric patterns were similar to the human and baboon patterns. In addition, samples from pregnant chimpanzees demonstrate a pronounced quantitative anodal shift in relative band densities, a shift also observed in pregnant humans. This shift was not observed in samples from pregnant baboons. TBG should prove to be a useful X-linked genetic marker in baboons and provides a model of serum protein changes in pregnancy, at least in humans and chimpanzees.
Animals↗
The Gardner syndrome. Significance of ocular features.
Gardner syndrome is a dominantly inherited familial cancer syndrome characterized by intestinal polyposis, bony hamartomata, and various soft tissue tumors. The risk of malignancy during adult life is essentially 100%, but as yet no phenotypic marker nor biochemical or serological linkage have been useful to identify the presence of the gene in early life. We studied three families in which multiple and bilateral patches of congenital hypertrophy of the retinal pigment epithelium are related uniquely to other phenotypic features of the Gardner gene. This readily identifiable characteristic may be useful to identify early in life individuals at risk for malignancy. We also suggest that the Gardner syndrome may be genetically heterogeneous.
Adult↗
Glycosylated hemoglobin determination from capillary blood samples. Utility in an epidemiologic survey of diabetes.
Total glycosylated hemoglobin was measured from capillary blood specimens obtained from a sample of 1880 individuals of Mexican-American ancestry residing in Starr County, Texas, between January 1981 and February 1982, as part of an epidemiologic survey to assess the prevalence of noninsulin-dependent diabetes mellitus (Type II). No significant difference was found between males and females. Diabetics were found to have significantly higher levels of glycosylated hemoglobin than nondiabetics. However, among diabetics, there was no significant difference between newly diagnosed and known diabetics, and known diabetics taking medication did not differ significantly from those not taking medication. An analysis of the specificity and sensitivity of glycosylated hemoglobin, fasting blood glucose, and casual blood glucose determinations as screening devices in a survey of diabetes prevalence reveals that glycosylated hemoglobin is superior to casual blood glucose determination. The conditions under which various screening devices might be more effective are discussed.
Diabetes Mellitus, Type 2↗
Atypical vitelliform macular dystrophy in a 5-generation family.
Five generations of a family with autosomal dominant atypical vitelliform macular dystrophy (A-VMD) were studied. This dystrophy is similar to autosomal dominant Best's vitelliform dystrophy (B-VMD) but clinically more closely resembles sporadic pseudovitelliform macular degeneration (P-VMD). Of the family members who were 14 years or older 43 (24 females and 19 males) of the 101 at risk (43%) were affected. Vision varied from 20/20 to 20/200. Field defects and tritan colour defects were invariably present only when vision was less than or equal to 20/200, but these defects were sometimes present when vision was good. The electrooculographic studies (LP/DT ratios) in this family were found to be normal or reduced and did not correlate with visual acuity. Minimal retinal findings consisted of macular or extramacular punctate yellow lesions or both in the retinal pigment epithelium, which were hypofluorescent by angiography, and retinal pigment epithelial defects in the temporal nerve fibre bundle, which were hyperfluorescent by angiography. Fluorescein angiographic changes were invariably present when retinal lesions were noted, and this was the most reliable test in identifying genotypically affected family members with minimal phenotypic expression.
Adolescent↗
Possible heterogeneity in the phosphoglycolate phosphatase (PGP)-haptoglobin alpha (HPA) linkage.
Previous investigators have reported loose linkage in both sexes for phosphoglycolate phosphatase (PGP) and haptoglobin alpha (HPA). We present results of linkage studies between PGP and HPA in two data sets, one from Houston and the other an update of an earlier report from Los Angeles. Using quadratic interpolation to estimate the male (theta m) and female (theta f) recombination values from bivariate lod tables, we found for the Houston data that theta m = 0.43 and theta f = 0.03 at the maximum lod score of z = 2.23. For the Los Angeles series, we found that theta m = 0.31, theta f = 0.48, and z = 0.27. We invoke heterogeneity in the recombination value in different families as an explanation of our findings. We also recommend that bivariate lod tables should always be generated, even though not reported. This is because the usual assumption of theta m = theta f (and, rarely, theta f = 1.8 theta f) under which lod scores are computed may be invalid in many cases.
California↗
Genetics and epidemiology of gallbladder disease in New World native peoples.
Native peoples of the New World, including Amerindians and admixed Latin Americans such as Mexican-Americans, are highly susceptible to diseases of the gallbladder. These include cholesterol cholelithiasis (gallstones) and its complications, as well as cancer of the gallbladder. Although there is clearly some necessary dietary or other environmental risk factor involved, the pattern of disease prevalence is geographically associated with the distribution of genes of aboriginal Amerindian origin, and levels of risk generally correspond to the degree of Amerindian admixture. This pattern differs from that generally associated with Westernization, which suggests a gene-environment interaction, and that within an admixed population there is a subset whose risk is underestimated when admixture is ignored. The risk that an individual of a susceptible New World genotype will undergo a cholecystectomy by age 85 can approach 40% in Mexican-American females, and their risk of gallbladder cancer can reach several percent. These are heretofore unrecognized levels of risk, especially of the latter, because previous studies have not accounted for admixture or for the loss of at-risk individuals due to cholecystectomy. A genetic susceptibility may, thus, be as "carcinogenic" in New World peoples as any known major environmental exposure; yet, while the risk has a genetic basis, its expression as gallbladder cancer is so delayed as to lead only very rarely to multiply-affected families. Estimates in this paper are derived in part from two studies of Mexican-Americans in Starr County and Laredo, Texas.
Adolescent↗
Genetic differentiation in Dogrib Indians: serum protein and erythrocyte enzyme variation.
Fourteen polymorphic and 24 monomorphic serum protein and erythrocyte enzyme systems were studied in Dogrib Indians living in three villages in the Northwest Territories of Canada. New information on the subtypes of Gc is provided, as is the description of a new variant at the galactose-1-phosphate uridyl transferase (GALT) locus. Maximum European admixture in the Dogrib is 8.7%. Contingency chi-square analysis indicates significant genetic differentiation among the villages. Nei's (1973) GST = .0083 +/- .0022 over 36 systems, including blood groups. This compares favorably with GST obtained for three Macushi subdivisions, but appears to exceed that observed among the Xavante Indians of South America.
Adult↗
The analysis of hidden electrophoretic variation: interspecific electrophoretic differentiation and amino acid divergence.
In a study of 25 human variants and 23 "evolutionary alleles" of hemoglobin we show that intraspecific and interspecific patterns of electrophoretic variability are not comparable. Significant deviation from the predicted electrophoretic differentiation between evolutionary alleles is normally found only when amino acid sequence divergence exceeds 10%. When two sequences had diverged at less than 30 out of 287 amino acid residues sites, only 7% of comparisons showed significant deviations from the expected difference of electrophoretic mobility, while significant deviation was shown by 57% of comparisons involving 30-40 residue differences, by 79% in the case of 51-60 differences and by all of the comparisons involving more than 60 differences. In contrast, human variants, which differ by only one or two amino acid residues (less than 1% difference), had significant deviations in 58% of comparisons. Those mutations that appear as fixed differences in the evolutionary material probably represent only a subset of the mutations which can appear within the species. The results suggest that statistical comparisons such as genetic distance may not measure the same process within a species as between species. This is due not to inherent problems with the statistic, but rather to inherent differences in the nature of molecular changes that are detectable by electrophoresis at different stages of population divergence.
Amino Acid Sequence↗
Diabetes among Mexican Americans in Starr County, Texas.
An increasing body of evidence suggests that diabetes mellitus constitutes a major health burden among the Mexican-American population. For example, county-wide death rates in Texas attributable to diabetes from 1970-1981 range from 2.5-52.0 diabetes deaths per 1000 total deaths with the highest rates generally occurring in counties whose populations are more than 75% Spanish ancestry. To assess the prevalence and morbidity of noninsulin-dependent diabetes mellitus among Mexican Americans, 14% of the Starr County, Texas, population (97% Mexican-American) was randomly sampled. The reference population, sampling strategy, and screening results are described. Age-specific prevalences of diabetes for males ranged from 0% in males aged 15-24 years to 17.6% in those above 75 years of age. Rates for females ranged from 0.4% in those aged 15-24 years to a high of 19.0% in the 55- to 64-year age group. In both sexes, the rates are relatively low for persons under age 45 with a sharp increase in those aged 45-54 years and high rates prevailing in the older age groups. Comparisons of the rates in Starr County to those of the general US population indicate a two- to fivefold greater risk in Starr County. In terms of impact on this community, these results imply that over 50% of individuals older than 35 years are directly affected by diabetes by virtue of their having the disease or by being a first-degree relative of a diabetic.
Adolescent↗
Application of isozymes to the mapping of inherited ophthalmic disorders.
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Acid Phosphatase↗
Management of preterm premature rupture of membranes.
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Female↗
Linkage of atypical vitelliform macular dystrophy (VMD-1) to the soluble glutamate pyruvate transaminase (GPT1) locus.
One hundred twenty-eight blood samples were drawn from members of a single family with atypical vitelliform macular dystrophy (VMD-1) characterized by variable expressivity in affected members of at least 5 generations. Because of the late onset of detectable retinal lesions in most family members, phenotype data from only 93 individuals who were at least 14 years of age were analyzed for linkage. Phenotype data from the remaining 35 members of the family who were under age 14 were excluded from the analysis. Maximum-likelihood analysis for linkage between VMD-1 and 13 biochemical and serological markers in the family demonstrated linkage between VMD-1 and the soluble glutamate pyruvate transaminase (GPT1) locus, which has been tentatively assigned to the short arm of chromosome 16. A maximum lod score of Z = 4.34 (odds favoring linkage of approximately 22,000 to 1) was obtained at a recombination fraction of theta = .05.
Adolescent↗
Familial renal cell carcinoma with a 3;11 chromosome translocation limited to tumor cells.
Cytogenic studies were performed on the direct chromosome preparations of the renal cell carcinoma cells and the cultured peripheral blood lymphocytes of a patient with familial renal cell carcinoma. The results revealed a specific, acquired translocations (3p;11p) present in the majority of metaphases of the tumor, indicating that the development of renal cell carcinoma is associated with a deletion in the proximal end of 3p. Renal cell carcinoma is thus the third example--the first two being retinoblastoma and Wilms' tumor--of a chromosomal deletion occurring germinally or somatically in association with a specific tumor. This finding adds further support to the existence of specific human cancer genes.
Adenocarcinoma↗
Familial cavernous angiomas: natural history and genetic study over a 5-year period.
In a kindred of 122 individuals we found 5 individuals with cerebral vascular malformation, 3 representing typical cavernous angiomas. The condition was inherited as an autosomal dominant trait with variable expressivity. Forty-three relatives were examined prospectively by cranial computed tomography (CCT) and lesions were found in 15; 7 were followed prospectively with CCT scans for 5 years. Angiography in 5 of these cases failed to demonstrate the lesion. In 3 patients with previously normal CCT scans a change in blood volume or membrane permeability allowed visualization of the lesion on contrast scans. In 2 individuals, both parents of affected children, a normal CCT scan was found. This emphasizes the limitations of CCT in detecting this disorder. Biochemical and red blood cell immunological genetic linkage studies were done in 36 persons. No linkage was found with any of the markers. The natural history of this disorder, characterized by marked clinical and radiographic variation in site of lesion, and the timing and severity of intracranial hemorrhage, make it a useful model for investigating contributing factors and consequences of intracranial hemorrhage in general. For at-risk and affected patients early and sequential CCTs are necessary. Familial cavernous angioma should be included in the differential diagnosis of all young persons presenting with cerebrovascular impairment, seizures, intracranial calcifications or hemorrhage.
Adolescent↗