genetics…

Copy and paste into this window to access results from our Google index.

Medical experts recommend this detailed explanation.

[ Find Organization | Index Page ]

Relevant search terms and links to related topics…

genetics, homozygous, inheritance, heterozygous, inheritance patterns, heredity, heritable, genetic markers, common knowledge that a person's appearance, height, hair color, skin color, eye color, determined by genes, mental abilities, natural talents, heredity, the susceptibility to acquire certain diseases, an inherited, abnormal trait, anomaly, have no consequence to a person's health, a white patch of hair, an extended ear lobe, of minor consequence, color blindness, have dramatic effect on the quality, length of life, most genetic disorders, genetic counseling is advised, want to seek prenatal diagnosis, terms anomaly, abnormality, defect, syndrome, not used consistently, not have precise definitions, human beings have cells, 46 chromosomes, -2 sex chromosomes, 22 pairs of autosomal, non-sex, chromosomes, males, "46, xy", females, "46, xx", chromosomes, made up of extremely long dna molecules in combination, chromosomal proteins, genes, defined by intervals, along one, the dna molecules, location, the gene, the locus, most genes carry information which is necessary to synthesize a protein, pairs of autosomal chromosomes, mother, father, carry basically the same information, each has the same genes, slight variations, in the dna sequence of nucleotide bases in each gene, slight variations occur in less than 1%, the dna sequence, produce different variants of a particular gene, alleles, information contained, in the nucleotide sequence of a gene is transcribed to mrna, messenger rna, by enzymes, in the cell's nucleus, translated to a protein, in the cytoplasm, protein a structural constituent of a given tissue, an enzyme which catalyzes a chemical reaction, a hormone, many other potential functions, proteins, a gene is abnormal, code, an abnormal protein, an abnormal amount, a normal protein, the autosomal chromosomes, paired, 2 copies of each gene, one of these genes is defective, code, sufficient protein, that no disease is clinically apparent, a recessive disease, gene is said to be inherited, recessive pattern, case of a recessive disease, one abnormal gene is inherited, child, not show clinical disease, each child of these parents, stand a 50% chance of inheriting the abnormal gene, one abnormal gene produces disease, a dominant hereditary disorder, case of a dominant disorder, one abnormal gene is inherited from mom, dad, child, likely show the disease, one abnormal gene is termed heterozygous, gene, a child receives an abnormal recessive disease gene from both parents, child, homozygous, gene, two parents, each heterozygous, particular recessive disease gene, each child has a 25% chance of homozygous, gene, showing the disease, one parent is homozygous, heterozygous, each child has a 50% chance of homozygous, genetic disorders, all diseases have a genetic component, the importance of that component, disorders where genetics play an important role, -called genetic diseases, single gene defects, chromosomal disorders, multifactorial, a single gene disorder, mendelian disorder, one that is determined by a single genetic locus, specific allele on one, members of a chromosome pair, single gene defects, rare, a frequency of less than 1 in 200 births, known single gene disorders, combined impact is significant, incidence of serious single gene disorders is estimated to be, 1 in 200 births, single-gene disorders, characterized by the pattern of transmission in families, a pedigree, term "kindred" includes the relatives outside, the immediate nuclear family, individual that initially comes to light, of immediate interest, the proband, brothers, sisters, the proband, siblings, 5 basic patterns of single gene inheritance, autosomal dominant, autosomal recessive, x-linked dominant, x-linked recessive, maternal, mitochondrial, inheritance, observed effect of an abnormal gene, appearance of a disorder, the abnormal phenotype, a phenotype expressed, in the same way, in both homozygotes, heterozygotes, dominant, a phenotype expressed only in homozygotes, x-linked traits, expressed in males but not females, recessive, heterozygotes, recessive gene, carriers, don't express the phenotype clinically, frequently be identified by sensitive laboratory methods, in autosomal dominant inheritance, abnormality, abnormalities, appear in every generation, every affected child has an affected parent, each child of an affected parent has a 50% chance of inheriting the disease, normal members, the family, not transmit the disease, males, females, equally likely to have the disease, to transmit the disease, male-to-male transmission, unlike, x-linked inheritance, males, have unaffected daughters, unlike, x-linked dominant inheritance, in autosomal recessive inheritance, parents of an affected individual, not express the disease, on average, chance of an affected child's brothers, sisters having the disease, 1 in 4, males, females, equally likely to be affected, child to have symptoms of an autosomal recessive disorder, child must receive the defective gene from both parents, most recessive disorders, rare, a child is at increased risk of a recessive disease parents, related individuals, more likely to have inherited the same rare gene, a common ancestor, in x-linked recessive inheritance, incidence, the disease is much higher in males than females, the abnormal gene, carried on the x chromosome, males, not transmit it to sons, transmit it to daughters, presence of one normal x chromosome masks the effects, the x chromosome, the abnormal gene, the daughters of an affected man appear normal, all carriers, the abnormal gene, sons of these daughters then have a 50% chance of receiving the defective gene, in x-linked dominant inheritance, presence, the defective gene appears in females, also a normal x chromosome present, males pass the y chromosome to sons, males, not have affected sons, all of daughters, sons, daughters of affected females, 50% chance of getting the disease, examples of single gene disorders, autosomal recessive, cystic fibrosis, cf, very common hereditary disorder, 1 out of caucasian births, normal function, a particular protein, transport chloride ions into certain cells, deficiency of this protein somehow results, in the accumulation of thick mucus, in the lungs, parts, situation compromises respiration, greatly increases the chance of pulmonary infections, individuals rarely survive, age of 40, phenylketonuria, pku, common genetic disorder, 1 out of 12, 000 births, a deficient enzyme required, the metabolism, the amino acid phenylalanine, failure to recognize the disorder early in life results in mental retardation, many states, require all newborns to be screened, alpha-1-antitrypsin, aat, deficiency, disorder seen in, 1 out of births, normal function, the protein, inhibit enzymes which escape from white blood cells, in the process of destroying invading bacteria, individuals, more likely to develop emphysema than usual, sickle cell anemia, disorder common in individuals, an african ethnic background, high frequency, the gene probably relates, fact that the heterozygotes, resistant to malaria, homozygotes have a predominance of an abnormal hemoglobin in red blood cells, abnormal protein causes, red blood cells to assume abnormal shapes, to lyse, a process of disintegration, dissolution, in small blood vessels under conditions of reduced oxygen pressure, ada deficiency, rare immunodeficiency disorder, the "boy, bubble" disease, deficiency of an enzyme, adenosine deaminase, enzyme is important, the normal function, lymphocytes, the primary components, the immune system, disease has the distinction, the first to be treated effectively by genetic engineering, the patient's cells, removed, injected, a normal gene, reintroduced, x-linked recessive, duchenne muscular dystrophy, very common, 1 out of 3, 500 male births, disorder that results, an abnormal muscle protein, muscles of young boys gradually deteriorate, muscles required, normal respiration, become ineffective, boys, die of pulmonary infections, the age of 20, hemophilia a is seen in 1 out of male births, defective protein, coagulation factor viii, normal blood clotting, individuals, require injections, the protein, transfusion of blood products, prevent internal bleeding, genetically engineered protein became available, many of these individuals contracted viral hepatitis, aids, a result of many transfusions, autosomal dominant, familial hypercholesterolemia, fhc, fairly common disorder, 1 out of 500 individuals, heterozygous, gene codes, protein which is found on the external surface of most, the body's cells, -called receptor protein mediates the uptake of cholesterol, cells, cholesterol is transported, in the blood by a lipoprotein, ldl, ldl can't get into cells, increases to high levels, in the blood, high levels of ldl, its associated cholesterol, increases the risk of developing arteriosclerosis, coronary artery disease, homozygous individuals, 1 out of, 000 births, have extremely high levels of ldl, develop coronary heart disease in childhood, huntington's disease, neurodegenerative disease which doesn't appear, approximately age 30, has, become possible to test, the presence, the abnormal gene at any age, information of great interest to individuals who know they, develop the disease later in life, wish to modify plans in regards to marriage, childbearing, individuals prefer not to know, the prognosis is grim, no effective treatment, x-linked dominant, a few, disorders, x-linked dominant, one of these is hypophosphatemic rickets, vitamin d -resistant rickets, in this case a protein, in the kidneys is defective, protein, transports phosphate, urinary filtrate back, blood, phosphate, in the blood is much lower than normal, bones, chronically stimulated to release calcium, phosphate by hormones parathormone, results in fragile, abnormally structured bones, chromosomal disorders, in chromosomal disorders, defect is due not to a single gene, to an excess, deficiency, the genes contained, whole chromosome, chromosome segment, down syndrome, most common chromosomal disorder, 1 out of 800, individuals have an extra copy of chromosome 21, unbalanced set of genes results in mild to moderate mental retardation, numerous physical changes, common examples, klinefelter syndrome, 1 out of males, turner syndrome, 1 out of females, multifactorial disorders, the most common diseases which affect humans undoubtedly involve interactions of numerous genes, coronary heart disease, hypertension, stroke, various kinds of cancer, currently active areas of research, mitochondrial dna-linked disorders, mitochondria, small organelles present in most, the body's cells which function, in the conversion of certain chemicals in our food, presence of oxygen, common currency of energy inside cells, atp, mitochondria contain own private dna, in recent years, than 20 hereditary disorders have been shown to result from mutations in mitochondrial dna, mitochondria come only, egg, inherited exclusively, mother, a mitochondrial disorder, exhibit maternal inheritance, individuals related by a maternal relative, at risk, fathers, not pass on the disease, mitochondrial disorders, appear at any age, a wide variety of non-specific symptoms, signs, disorders, metabolic disturbances, developmental delay, blindness, hearing loss, heart rhythm problems, short stature, gastrointestinal problems.