Autosomal dominant or recessive? Flashcards
In autosomal dominant conditions, both homozygotes and heterozygotes manifest disease. TRUE/FALSE?
TRUE (there is no carrier state)
What gender is most commonly affected in autosomal dominant conditions?
both males and females affected
In autosomal dominant conditions, only affected individuals can pass on disease. TRUE/FALSE?
TRUE
If a patient affected by a autosomal dominant conditions decides to have children, what percentage of their children will be affected by the disease?
disease is passed on to 50% of children
Autosomal dominant conditions normally appear in every generation. TRUE/FALSE?
TRUE
Describe the concept of non-penetrance
lack of clinical signs and symptoms (normal phenotype) despite abnormal gene.
E.g. 40% otosclerosis
What is it called when a new mutation occurs in a child whose parents are not affected by an autosomal dominant condition?
sporadic mutation (e.g. common in achondroplasia ~70% sporadic mutations)
Describe the general “rule” when trying to determine if a condition is likely autosomal dominant or recessive?
Autosomal recessive = ‘metabolic’
Autosomal dominant = ‘structural’
Notable exceptions:
- metabolic conditions “hyperlipidaemia type II” and “hypokalaemic periodic paralysis” are autosomal dominant
- ‘structural’ conditions such as “ataxia telangiectasia” and “Friedreich’s ataxia” are autosomal recessive
Achondroplasia
Autosomal dominant
Acute intermittent porphyria
Autosomal dominant
Adult polycystic disease
Autosomal dominant
Antithrombin III deficiency
Autosomal dominant
Ehlers-Danlos syndrome
Autosomal dominant
Familial adenomatous polyposis
Autosomal dominant
Hereditary haemorrhagic telangiectasia
Autosomal dominant
Hereditary spherocytosis
Autosomal dominant
Hereditary non-polyposis colorectal carcinoma
Autosomal dominant
Huntington’s disease
Autosomal dominant
Hyperlipidaemia type II
Autosomal dominant
Hypokalaemic periodic paralysis
Autosomal dominant
Malignant hyperthermia
Autosomal dominant
Marfan’s syndromes
Autosomal dominant
Myotonic dystrophy
Autosomal dominant
Neurofibromatosis
Autosomal dominant
Noonan syndrome
Autosomal dominant
Osteogenesis imperfecta
Autosomal dominant
Peutz-Jeghers syndrome
Autosomal dominant
Retinoblastoma
Autosomal dominant
Romano-Ward syndrome
Autosomal dominant
tuberous sclerosis
Autosomal dominant
Von Hippel-Lindau syndrome
Autosomal dominant
Von Willebrand’s disease
Autosomal dominant
**type 3 von Willebrand’s disease (most severe form) is inherited as an autosomal recessive trait. Around 80% of patients have type 1 disease
Albinism
Autosomal recessive
Ataxic telangiectasia
Autosomal recessive
Congenital adrenal hyperplasia
Autosomal recessive
Cystic fibrosis
Autosomal recessive
Cystinuria
Autosomal recessive
Familial Mediterranean Fever
Autosomal recessive
Fanconi anaemia
Autosomal recessive
Friedreich’s ataxia
Autosomal recessive
Gilbert’s syndrome
Autosomal recessive
*although some textbooks still list as autosomal dominant
Glycogen storage disease
Autosomal recessive
Haemochromatosis
Autosomal recessive
Homocystinuria
Autosomal recessive
Lipid storage disease: Tay-Sach’s, Gaucher, Niemann-Pick
Autosomal recessive
Mucopolysaccharidoses: Hurler’s
Autosomal recessive
PKU
Autosomal recessive
Sickle cell anaemia
Autosomal recessive
Thalassaemias
Autosomal recessive
Wilson’s disease
Autosomal recessive
