Search results for "HETEROZYGOTE ADVANTAGE"
showing 6 items of 56 documents
The selective advantage of cystic fibrosis heterozygotes tested by aDNA analysis: A preliminary investigation
2000
Recently a heterozygote advantage was suggested to explain the high incidence (1:25 carrier individuals in Europeans) of the cystic fibrosis gene. This selective advantage was speculated to be due to a high resistance to chloride-secreting diarrhea, including cholera. Up to now the major efforts to test directly this hypothesis have been limited to animal models.
Estrogen receptor alpha polymorphism modifies the association between childhood exercise and bone mass: follow-up study.
2007
This follow-up study confirms our previous findings that the ER-α PvuII polymorphism (Pp) modulates the association between exercise and bone mass. The differences in bone properties of girls with consistently low physical activity (LLPA) and consistently high physical activity (HHPA) were evident only in those bearing the heterozygote ER-α genotype (Pp). In particular, areal bone mineral density of the total femur, bone mineral content and areal bone mineral density of the femoral neck, and bone mineral content and cortical thickness of the tibia shaft were significantly (p < .05) lower in the Pp girls with LLPA than in their HHPA counterparts. These findings might partly explain the ge…
Identification of a novel mutation of MTP gene in a patient with abetalipoproteinemia.
2011
Abetalipoproteinemia (ABL), or Bassen-Kornzweig syndrome, is a rare autosomal recessive disorder of lipoprotein metabolism, characterized by fat malabsorption, hypocholesterolemia retinitis pigmentosa, progressive neuropathy and acanthocytosis from early infancy. We describe the clinical and molecular characterization of a 6-month-old infant born of consanguineous, apparently healthy parents from Iran. The patient was hospitalized because of failure to thrive, greasy stool and vomiting. The patient's serum lipid profile, the clinical phenotype and the duodenal histology suggested the clinical diagnosis of ABL. The MTP gene analysis by direct sequencing revealed a novel homozygous mutation (…
Disease manifestations and X inactivation in heterozygous females with Fabry disease
2006
Aim: Fabry disease is an X-linked lysosomal storage disorder characterized by an accumulation of neutral glycosphingolipids in multiple organ systems caused by α-galactosidase A deficiency due to mutations in the GLA gene. The majority of heterozygous females show the characteristic signs and symptoms of the disease, and some of them are severely affected. The current hypothesis for the occurrence of disease manifestations in females is skewed X inactivation favouring the mutant GLA allele. Method: We analyzed the patterns of X inactivation in the leukocytes of 28 biochemically and genetically characterized symptomatic Fabry disease heterozygotes and their correlation with clinical and bioc…
Ischemic Type Biliary Lesions nach orthotoper Lebertransplantation - ein immunologisches Problem?
2004
Ischemic type biliary lesions (ITBL) are a major complication following orthotopic liver transplantation (OLT). In many cases re-OLT is indicated. Multiple factors have been claimed to be reasonable for ITBL; here we present a new immunological risk factor: CC-Chemokines play a key role in the recruitment of leukocytes during ischemia-reperfusion damage and acute rejection. Therefore the CC-chemokine-receptor 5 (CCR5) and its functionless CCR5-delta-32-polymorphism (CCR5Δ32) might have an influence on the grafts pathology after OLT. In 146 patients after OLT the CCR5 was analyzed with regard to the CCR5Δ32 by PCR. 120 patients (82,1%) showed a normal receptor (wildtype) whereas 26 patients …
Heterozygote advantage and pleiotropy contribute to intraspecific color trait variability
2022
The persistence of intrapopulation phenotypic variation typically requires some form of balancing selection because drift and directional selection eventually erode genetic variation. Heterozygote advantage remains a classic explanation for the maintenance of genetic variation in the face of selection. However, examples of heterozygote advantage, other than those associated with disease resistance, are rather uncommon. Across most of its distribution, males of the aposematic moth Arctia plantaginis have two hindwing phenotypes determined by a heritable one locus-two allele polymorphism (genotypes: WW/Wy = white morph, yy = yellow morph). Using genotyped moths, we show that the presence of o…