Human Biology Unit 4

Diseases and Disorders - mutations

Achromatopsia

An inherited form of total colour blindness

Albinism

An inherited inability to produce pigment in hair, skin, and eyes.

Anaemia

Condition in which there is a reduced amount of haemoglobin in the blood, or a reduced number of red blood cells.

Cri-du-chat syndrome

Rare genetic disorder caused by missing part of chromosome 5

Cystic fibrosis

Disorder controlled by a recessive allele carried on an autosome that is incurable but can be detected during foetal development.

Mucus-secreting glands, particularly in the lungs and pancreas, become fibrous and produce abnormally thick mucus, resulting in, among other things, chest infections.

Downsyndrome/trisomy 21

A genetic disorder resulting from an extra copy of chromosome 21 or an extra part of chromosome 21.

Duchenne Muscular Dystrophy (DMD)

A genetic disease resulting in wasting leg muscles, then arms, shoulders, and chest.

Klinefelter syndrome

A genetic disorder resulting from inheritance of two X chromosomes and one Y chromosome.

Patau syndrome

A genetic disorder resulting from an extra copy of chromosome 13

Phenylketonuria (PKU)

Inherited disease resulting in damage to growing brain. Causes extreme intellectual deficiency, a tendency towards epileptic seizures, and failure to produce normal skin pigmentation.

Sickle-cell anaemia

Inherited disease causing early death. Results from the inheritance of two alleles for sickle-cell anaemia.

Tay-Sachs disease (TSD)

A genetic disorder caused by a missing enzyme that results in fatty substances accumulating in the nervous system.

Turner syndrome

A genetic disorder resulting from inheritance of one X chromosome and no other sex chromosome.