Homozygous

Approximately 2% of all COPD patients suffer from homozygous al-AT deficiency. Intravenous infusion of replacement protein twice weekly in patients with established al-AT deficiency is approved in the US but not in Europe. The effectiveness of this extremely expensive treatment is not yet known. 

A co-dominant is a heritable trait in which both alleles of a polymoiphism are expressed and are reflected in the phenotype. The phenotype of heterozygous carriers is in between the phenotypes of the two homozygous genotypes. 

Mice homozygous for an ETA receptor gene disruption show craniofacial malformations, such as cleft palate, micrognathia, microtia and microglossia. ETA (—/—) mice die shortly after birth due to respiratory failure. Mice with an ET-l-null mutation show the same cranciofacial malformations and, in addition, cardiovascular disorders (e.g. septal defects, abnormal cardial outflow tract, aortic arch and subclavian arteries). 

The genetic constitution of an organism, which it has inherited from its parents. The genotype refers to the particular combination of alleles at specified loci present in an organism homozygous individuals have identical alleles and heterozygous individuals have different alleles. 

Mice that are homozygous for a disrupted Bx or B2 receptor gene are healthy, fertile and normotensive. In Bx-deficient mice, bacterial lipopolysaccharide-induced hypotension is diminished and the recruitment of polymorphonuclear leukocytes to the sites of tissue injury is impaired, and the animals show signs of hypoalgesia. Deletion of the B2 gene in mice leads to salt-sensitive hypertension and altered nociception. 

Cysteine-cysteine chemokine receptor 5 (CCR5) A 32-bp deletion with a population frequency of about 0.1 in Caucasians results in truncated nonfunctional receptor. Carriers of this variant are partially protected from HIV infection, particularly the homozygous carriers. 

Liu R, Paxton WA, Choe S, Ceradini D, Martin SR, Horuk R, MacDonald ME, Stuhlmann H, Koup RA, Landau NR (1996) Homozygous defect in HlV-1 coreceptor accounts for resistance of some multiply-exposed individuals to HIV-1 infection. Cell 86 367-377... 

Thanatophoric (Gk thanatos "death" + pharos "bearing") dysplasia is the most common neonatal lethal skeletal dysplasia, displaying features similar to those of homozygous achondroplasia. 

Malignant hyperthermia also occurs in swine. Susceptible animals homozygous for malignant hyperthermia respond to stress with a fatal reaction (porcine stress syndrome) similar to that exhibited by humans. If the reaction occurs prior to slaughter, it affects the quality of the pork adversely, resulting in an inferior product. Both events can result in considerable economic losses for the swine industry. 

Work with Intact Glycophorins Derived from Heterozygous, and Homozygous,... 

A search for Heinz bodies Is helpful In the detection of an unstable hemoglobin, of a-thalassemia, homozygous 3-thalas-semla and related abnormalities, because hemoglobin often precipitates In the red cells of patients with one of these disorders. Inclusion bodies may consist of precipitated unstable hemoglobin, of 3 chalns (In a-thalassemia), or of a chains (In thalassemia) ... 

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