Genetic Disorders Quiz

A genetic disorder is a health problem caused by one or more abnormalities in the ______

It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a ______ abnormality

Although polygenic disorders are the most common, the term is mostly used when discussing disorders with a single genetic cause, either in a gene or ______

The mutation responsible can occur spontaneously before embryonic development (a de novo mutation), or it can be inherited from two parents who are carriers of a faulty gene (autosomal recessive inheritance) or from a parent with the disorder (autosomal ______ inheritance)

When the genetic disorder is inherited from one or both parents, it is also classified as a ______ disease

Genomic imprinting and uniparental disomy, however, may affect inheritance patterns. The divisions between recessive and dominant types are not 'hard and fast', although the divisions between autosomal and X-linked types are (since the latter types are distinguished purely based on the chromosomal location of the gene). For example, the common form of dwarfism, achondroplasia, is typically considered a dominant disorder, but children with two genes for achondroplasia have a severe and usually lethal skeletal disorder, one that achondroplasics could be considered carriers for. Sickle cell anemia is also considered a recessive condition, but heterozygous carriers have increased resistance to malaria in early childhood, which could be described as a related dominant condition. When a couple where one partner or both are affected or carriers of a single-gene disorder wish to have a child, they can do so through in vitro fertilization, which enables preimplantation genetic diagnosis to occur to check whether the embryo has the genetic disorder.Most congenital metabolic disorders known as inborn errors of metabolism result from single-gene defects. Many such single-gene defects can decrease the fitness of affected people and are therefore present in the population in lower frequencies compared to what would be expected based on simple probabilistic calculations. === Autosomal dominant === Only one mutated copy of the gene will be necessary for a person to be affected by an autosomal dominant disorder. Each affected person usually has one affected parent.: 57  The chance a child will inherit the mutated gene is 50%. Autosomal dominant conditions sometimes have reduced penetrance, which means although only one mutated copy is needed, not all individua.

Due to the significantly large number of ______ disorders, approximately 1 in 21 people are affected by a ______ disorder classified as 'rare' (usually defined as affecting less than 1 in 2,000 people). Most ______ disorders are rare in themselves.Genetic disorders are present before birth, and some ______ disorders produce birth defects, but birth defects can also be developmental rather than hereditary. The opposite of a hereditary disease is an acquired disease. Most cancers, although they involve ______ mutations to a small proportion of cells in the body, are acquired diseases. Some cancer syndromes, however, such as BRCA mutations, are hereditary ______ disorders. == Single-gene == A single-gene disorder (or monogenic disorder) is the result of a single mutated gene. Single-gene disorders can be passed on to subsequent generations in several ways.

When a couple where one partner or both are affected or carriers of a single-gene disorder wish to have a child, they can do so through in vitro fertilization, which enables preimplantation genetic diagnosis to occur to check whether the ______ has the genetic disorder.Most congenital metabolic disorders known as inborn errors of metabolism result from single-gene defects. Many such single-gene defects can decrease the fitness of affected people and are therefore present in the population in lower frequencies compared to what would be expected based on simple probabilistic calculations. === Autosomal dominant === Only one mutated copy of the gene will be necessary for a person to be affected by an autosomal dominant disorder. Each affected person usually has one affected parent.: 57  The chance a child will inherit the mutated gene is 50%. Autosomal dominant conditions sometimes have reduced penetrance, which means although only one mutated copy is needed, not all individua.

Most congenital metabolic disorders known as inborn errors of metabolism result from single-gene defects. Many such single-gene defects can decrease the fitness of affected people and are therefore present in the population in lower frequencies compared to what would be expected based on simple probabilistic calculations. === Autosomal dominant === Only one mutated copy of the gene will be necessary for a person to be affected by an autosomal dominant disorder. Each affected person usually has one affected parent.: 57  The chance a child will inherit the mutated gene is 50%. Autosomal dominant conditions sometimes have reduced penetrance, which means although only one mutated copy is needed, not all individua.

The chance a child will inherit the mutated gene is 50%. Autosomal dominant conditions sometimes have reduced penetrance, which means although only one mutated copy is needed, not all individua.