As the largest of all the autosomes present in humans, chromosome 1 has the largest number of genes coding for the greatest variety of proteins. It is also the chromosome most susceptible to gene variations or mutation. Mutations or polymorphisms occur in at least 1% of the general population and as the largest chromosome, chromosome 1 is attributable for the greatest proportion of these mutations and the resulting diseases or disorders.

Nearly 890 diseases and disorders are associated with chromosome 1 abnormality. These includes several cancers as well as brain degenerative disorders such as Parkinson's disease and Alzheimer's disease. Other conditions including glaucoma and deafness are also associated with chromosome 1 abnormalities.

Diseases and disorders

Examples of the diseases that have been associated with abnormalities of chromosome 1 include:

• Brain degenerative diseases like Alzheimer's disease, Parkinson's disease and microcephaly.
• Various different cancers including breast cancer and prostate cancer
• Enzyme deficiencies such as carnitine palmitoyltransferase II deficiency, galactosemia, homocystinuria, 3-hydroxy-3-methylglutaryl-CoA lyase deficiency, maple syrup urine disease, medium-chain acyl-coenzyme A dehydrogenase deficiency and trimethylaminuria
• Collagen deficiency
• Eye disorders such as glaucoma and gelatinous drop-like corneal dystrophy
• Autosomal recessive deafness 36 and nonsyndromic deafness
• Factor V Leiden thrombophilia
• Charcot-Marie-Tooth disease and Ehlers-Danlos syndrome, Gaucher disease types 1, 2 and 3 and Gaucher-like disease, Hutchinson Gilford Progeria Syndrome, Muckle-Wells Syndrome, popliteal pterygium syndrome, Stickler syndrome, Usher syndrome and Van der Woude syndrome
• Hypothyroidism
• Familial adenomatous polyposis
• Hemochromatosis
• Various porphyrias
• Pheochromocytoma
• Hypertrophic cardiomyopathy