X linked family history
Some diseases only, or mainly, effect males. This occurs when the abnormal gene is on the X chromosome. Because men have one X chromosome and woman two, in recessive X linked diseases the normal X chromosome in the female will compensate to some extent the effect of the abnormal gene. Carrier mothers have a 50% chance of passing the X chromosome to their sons, who will have the disease. A boy will not get an X-linked disease from his father since boys get their fathers Y chromosome. Unlike X-linked recessive diseases, dominant X-linked diseases do effect females. Examples of X linked disorders:
Coffin Lowry Syndrome
Coffin Lowry syndrome is a rare genetic disorder characterized by
- mental retardation;
- abnormalities of the head and facial (craniofacial) area;
- large, soft hands with short...
X Linked Hypophosphatemia
X-linked hypophosphatemia (XLH) is known as the most common hereditary metabolic rickets with a prevalence of 1:20,000- 60,000. Manifestations are bone deformities (particularly bowing of...
Duchenne Muscular Dystrophy
Duchenne muscular dystrophy is an inherited, X-linked disease that affects about 1 in 3500 - 6000 males. DMD occurs as a result of a change...