Pernisiöösi

Pernisiöösi is a rare genetic disorder characterized by a deficiency in the enzyme purine nucleoside phosphorylase (PNP). This enzyme is crucial for the breakdown of purines, which are essential components of DNA and RNA. When PNP is deficient, purine metabolites, particularly deoxyguanosine, accumulate in the body, leading to toxic effects.

The primary manifestation of severe PNP deficiency is severe combined immunodeficiency (SCID). Individuals with this condition have a severely compromised immune system, making them highly susceptible to infections. They typically experience recurrent and persistent infections from early infancy, including bacterial, viral, and fungal pathogens. Neurological abnormalities can also be present, ranging from developmental delays and intellectual disability to movement disorders.

Mild or partial PNP deficiency can lead to less severe immune dysfunction and may not present with SCID. In such cases, individuals might experience recurrent infections but retain some immune function. The inheritance pattern of PNP deficiency is autosomal recessive, meaning that both parents must carry a copy of the mutated gene for their child to be affected. Diagnosis is usually confirmed through enzymatic assays and genetic testing. Treatment focuses on managing infections and, in severe cases, may involve hematopoietic stem cell transplantation or gene therapy.