The thalassaemias are a group of conditions characterised by reduced production of either the alpha (alpha-thalassaemia) or beta (beta-thalassaemia) chain of the haemoglobin molecule. There are two clinically significant forms of alpha-thalassemia. The more severe type is known as hemoglobin Bart hydrops fetalis (or Hb Bart) syndrome; the milder form is called HbH disease.
The thalassaemias are a group of conditions, all of which are characterised by reduced synthesis of either the alpha (alpha-thalassaemia) or the beta (beta-thalassaemia) chain of the haemoglobin molecule. Beta-thalassemia major is the most common of the thalassaemias and is suspected in an infant or child in the first two years of life presenting with severe microcytic anaemia and hepatosplenomegaly.
Congenital adrenal hyperplasia (CAH) is a group of inherited disorders that result in impaired hormone production from the adrenal glands.
Cystic fibrosis (CF) is a genetic disorder that affects mostly the lungs, but also the pancreas, liver, kidneys, and intestine. Long-term issues include difficulty breathing and coughing up mucus as a result of frequent lung infections.
Duchenne muscular dystrophy (DMD) is a disorder characterised by progressive muscle weakness commencing in the legs and pelvis, then extending to other muscles of the body.
Classic familial adenomatous polyposis (FAP) is a dominantly inherited cancer-susceptibility disorder. FAP occurs in about 3 in 100,000 people.
Familial hypercholesterolaemia (FH) is an autosomal dominant hyperlipidaemia disorder. Untreated FH results in premature coronary artery disease (typically fourth decade in men, up to 10 years later in women).
Familial medullary thyroid cancer (FMTC) is an inherited condition and a subtype of MEN2 (multiple endocrine neoplasia Type 2 – a hereditary endocrine cancer syndrome). Individuals with FMTC have a high probability of developing medullary thyroid cancer (MTC) with a lower probability of developing the other specific endocrine tumours (adrenal adenoma or parathyroid adenoma/ hyperplasia) usually associated with MEN2.
Haemophilia is an X-linked recessive bleeding disorder caused by partial or complete deficiency of blood clotting factors. The most common type is haemophilia A, which is caused by Factor VIII deficiency. Haemophilia A occurs in 1 in 5,000 male births. Haemophilia can result in prolonged bleeding and bruising after minor injury. Individuals with severe haemophilia may experience spontaneous bleeding in joints and muscles.
Breast cancer is the most commonly diagnosed cancer in the UK, affecting around 1 in 8 women during their lifetime. The majority of breast cancer is not due to an inherited condition, but it is important to recognise the less than 5% of breast cancer that occurs due to an inherited predisposition (inherited breast cancer). Two major genes associated with familial breast cancer are the BRCA1and BRCA2 genes.
Lynch syndrome (Hereditary non-polyposis colorectal cancer) is a cancer predisposition syndrome causing individuals to have a high risk of colorectal cancer. Women also have a high risk of endometrial cancer and an increased probability of developing ovarian cancer. It occurs due to the inheritance of an alteration in one of the mismatch repair genes (MLH1, MSH2, MSH6, and PMS2).