Lejeune Syndrome or Cri-du-chat (gallicism) involves deletion in the short arm of chromosome 5. One of the suppressed genes is responsible for the telomerase reverse transcriptase (TERT) gene that intervenes in the development processes. The condition is characterized by the cat's meow syndrome by the acute crying that the baby emits, facial dysmorphism and intellectual retardation, respiratory problems. It is believed that this disorder occurs from the development of the sperm or egg. More common in females.

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Periventricular heterotopia is a malformation of the brain caused by abnormal duplication of certain parts of chromosome 5. The disorder is characterized by abnormal neuronal migration, which leads to the accumulation of groups or neuronal nodules around fluid-filled cavities.

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Deletions on the long arm of chromosome 5 are often found in cancers such as Acute Myeloid Leukemia (AML) and Myelodysplastic Syndrome (MDS).

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Familial adenomatous polyposis (inherited) is caused by a suppression of coding in the long arm of chromosome 5 structure. This condition leads to the formation of polyps in the rectum and colon. Polyps are noncacergenic tissues, which have a high propensity to become cancer. It is an inherited condition.

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5q31.3  Microdeletion Syndrome is caused by the suppression of a small piece of chromosome 5 in the portion called q31.3 where at least three genes are suppressed, one of them called PURA or PUR- (alpha) that is of vital importance for cellular functioning since it is involved in gene transcription and DNA replication. The condition causes severe delay in the development of language and motor skills, low muscle tone or hypotonia, facial abnormalities (narrow front, eyes separated), breathing and swallowing problems (dysphagia) which can put the lives of the patients at risk. Patients may also suffer seizures and demyelination of the nervous system. Very rare disorder