autosomal recessive

Examples of autosomal recessive in the following topics:

• Polycystic Kidney Disease

  • There are two types of PKD: autosomal dominant polycystic kidney disease (ADPKD), and the less-common autosomal recessive polycystic kidney disease (ARPKD).
  • Autosomal dominant polycystic kidney disease (ADPKD) is the most common of all the hereditary cystic kidney diseases, with an incidence of 1:1,000 to 2:1,000 live births.
  • Studies show that the incidence of autosomal recessive polycystic kidney disease (ARPKD) is 1:20,000 live births, and is typically identified in the first few weeks after birth.

• Phenylketonuria (PKU)

  • Phenylketonuria (PKU) is an autosomal recessive metabolic genetic disorder due to a mutation in the phenylalanine hydroxylasegene gene.
  • Phenylketonuria (PKU) is an autosomal recessive metabolic genetic disorder characterized by a mutation in the gene for the hepatic enzyme phenylalanine hydroxylase (PAH), rendering it nonfunctional.
  • Because PKU is an autosomal recessive genetic disorder, both parents must have at least one mutated allele of the PAH gene.

• Congenital Adrenal Hyperplasia

  • Congenital adrenal hyperplasia refers to an autosomal recessive disease caused by mutated genes for enzymes that produce cortisol from cholesterol.
  • Congenital adrenal hyperplasia (CAH) refers to any of several autosomal recessive diseases resulting from mutations of genes for enzymes mediating the biochemical steps of production of cortisol from cholesterol by the adrenal glands (steroidogenesis).
  • Since CAH is a recessive gene, both the mother and father must be recessive carriers of CAH for a child to have CAH .
  • Due to advances in modern medicine, those couples with the recessive CAH genes have an option to prevent CAH in their offspring through preimplantation genetic diagnosis (PGD).
  • Since CAH is a recessive gene, both the mother and father must be recessive carriers of CAH for a child to have CAH (the child in red).

• Cystic Fibrosis

  • Cystic fibrosis (CF) is an autosomal recessive disorder leading to respiratory congestion, multiple organ failure, and metabolic changes.
  • Cystic fibrosis (also known as CF or mucoviscidosis) is an autosomal recessive genetic disorder affecting most critically the lungs and also the pancreas, liver, and intestine.
  • Although most people without CF have two working copies of the CFTR gene, only one is needed to prevent cystic fibrosis due to the disorder's recessive nature.
  • CF develops when neither gene works normally (as a result of mutation) and therefore has autosomal recessive inheritance.

• Sickle-Cell Disease

  • Sickle-cell disease is an autosomal recessive genetic blood disorder in which red blood cells assume a rigid sickle shape.
  • Sickle-cell disease (SCD), or sickle-cell anemia, is an autosomal recessive genetic blood disorder with overdominance characterized by red blood cells that assume an abnormal, rigid, and sickle shape.

• Glucosuria

  • When renal glycosuria occurs as an isolated finding with otherwise normal kidney function, the condition is thought to be inherited as an autosomal recessive trait.

• Complementation

  • Complementation refers to a relationship between two different strains of an organism which both have homozygous recessive mutations.
  • Since the mutations are recessive, the offspring will display the wild-type phenotype.
  • If there is an allele with an observable phenotype whose function can be provided by a wild type genotype (i.e., the allele is recessive), one can ask whether the function that was lost because of the recessive allele can be provided by another mutant genotype.
  • Because the mutations are recessive, there is a recovery of function in that pathway, so offspring recover the wild-type phenotype.
  • Two strains of flies are white eyed because of two different autosomal recessive mutations which interrupt different steps in a single pigment-producing metabolic pathway.

• Galactosemia and Glycogen Storage Disease

  • Galactosemia follows an autosomal recessive mode of inheritance that confers a deficiency in an enzyme responsible for adequate galactose degradation.

• Ataxia

  • Hereditary disorders causing ataxia include autosomal dominant ones such as spinocerebellar ataxia, as well as autosomal recessive disorders such as Friedreich's ataxia.

• Sex-Linked Traits

  • Until now, we have only considered inheritance patterns among non-sex chromosomes, or autosomes.
  • In addition to 22 homologous pairs of autosomes, human females have a homologous pair of X chromosomes, whereas human males have an XY chromosome pair.
  • Hemizygosity makes the descriptions of dominance and recessiveness irrelevant for XY males because each male only has one copy of the gene.
  • Females must inherit recessive X-linked alleles from both of their parents in order to express the trait.
  • The son of a woman who is a carrier of a recessive X-linked disorder will have a 50 percent chance of being affected.