The problems associated with FA include:
- congenital birth defects: the most common problems affect the thumb and radius (a bone in the lower arm). Other areas often affected are the heart, genitourinary system, other limbs and skin (with abnormal pigmentation - colouring of the skin)
- growth: short stature is common. Although deficiency of growth and thyroid hormones are seen in FA, their relevance to poor growth is not well understood.
- low blood cell counts (white cell, red cell and platelet counts): red blood cells carry oxygen around the body, white blood cells fight off infection and platelets help the blood clot. These often fall with age in FA leading to increased infections, anaemia and tiredness, and excessive bruising or bleeding. Many of those with abnormal blood counts during childhood will go on to develop aplastic anaemia.
- acute myeloid leukaemia (AML; see entry Leukaemia and other Allied Blood disorders) may occur, particularly during the second decade of life
- predisposition to cancer: many types of cancer are more frequent but the commonest complications are the development of acute myeloid leukaemia and head and neck or gynaecological cancers. Bone marrow changes, including the development of 'clones' of cells with chromosome changes or myelodysplastic syndrome, often occur before leukaemia develops.