A significant number of disorders arise because of mutation in receptors, in some cases blocking the normal signalling pathway simply because the receptor is absent or does not bind ligand, in other cases because the receptor is unregulated and constitutively active (e.g. stem cell myeloproliferative disorder). There are many types of receptors, ranging from the G-protein-coupled cell surface receptors, integrins, nuclear receptors, peroxisome proliferator-activated receptors PPAR, and receptors for neurotransmitters, hormones, signal sequences, and so on; mutations in any of these can cause problems. Receptors for light and sound, and defects in these systems, are covered under visual disorders and auditory disorders. Disorders in which a receptor dysfunction is implicated include acromegaly, Maroteaux-type acromesomelic dysplasia, Alagille's syndrome-2, Angelman's syndrome, Apert's syndrome, arrhythmogenic right ventricular dysplasia/cardiomyopathy-2, Bernard–Soulier syndrome, brachydactyly-A2, metaphyseal chondrodysplasia, Elejalde's syndrome, epidermolysis bullosa, familial hypercholesterolaemia, hereditary haemorrhagic telangiectasia, familial primary localized cutaneous amyloidosis, familial startle disease, fibrodysplasia ossificans progressiva, Glanzmann's thrombasthenia, haemochromatosis-3 and -4, hereditary lymphedema-1A, hereditary sensory and autonomic neuropathy-4, Hirschsprung's disease, various hormone disorders, hyperthyroidism and myasthenia gravis (in which there are antibodies to the receptor), autosomal recessive hypohidrosis, neonatal leukodystrophy, periodic fever, autosomal dominant pseudo- hypoaldosteronism, renal tubular dysgenesis, Schwartz–Jampel syndrome 2, some forms of stationary night blindness, congenital stiff person syndrome, and thrombocythaemia.
Subjects: Medicine and Health.