With advances in molecular genetics, the answer to the question is psoriasis hereditary, for the most part, is answered with yes. As an autoimmune disorder manifesting as layers of dead skin cells creating unsightly, thick red lesions, psoriasis affects nearly two percent of the population and often occurs with other autoimmune disorders, such as Crohn's disease, Lupus, HIV.
Results of human leukocyte antigen (HLA) studies have shown that psoriasis correlates with specific alleles or one of a pair of genes found on certain chromosomes that are passed from parents to children. This hereditability of psoriasis is based on the fundamental principle of Mendel's law of segregation that Gregor Mendel discovered over 100 years ago.
Based on investigations of families suffering from psoriasis, epidemiological studies, HLA studies and genome linkage scans, the case for psoriasis being a hereditary disease is legitimate. However, just because someone inherits the psoriasis gene does not automatically mean they will suffer from psoriasis flare-ups. Many genes containing alleles for various diseases and disorders exist within our DNA but "expression" of these diseases often depends on factors involving distinct environmental triggers.
According to an article published online at ScienceDaily.com (2006), psoriasis is a "multi-factorial" disease meaning individuals need to inherit other "disease" genes in addition to the psoriasis gene. Exposure to environmental stressors triggering the genes facilitates the expression of psoriasis symptoms. Is Psoriasis Hereditary?
Professor of Radiation Oncology and Dermatology Dr. James Elder states this concept in this way: "For every individual with psoriasis who carries the psoriasis gene, there are 10 other people with the gene who don't get psoriasis."
In the case for psoriasis, individuals harboring the gene need exposure to certain events before patches or lesions appear.
Severity of psoriasis outbreaks depends on the individual. A father who has mild psoriasis may pass on the genes to his son, who may suffer from severe psoriasis instead of the mild type. Doctors think the differing dimensions of psoriasis among family members are associated with how someone copes emotionally with the psoriasis and treatment protocols.
Psoriasis patches can appear on any part of the body. The most common places are the hands, feet, elbows, face, scalp and skin folds. A parent who suffers from lesions that primarily affect the face may pass on genes to children who experience psoriasis lesion only on the legs. In addition, a small psoriasis patch may appear on the arm, disappear in a few days, only to redevelop on another area of the body as a larger, more inflamed patch.
Response to various treatment plans depend on the individual, with some responding better than others to topical medications, UV light therapy and oral steroids. Dispensed by IV infusion or injection, biologic drugs are the newest treatments for psoriasis.
Protein-based biologics are synthesized from living cells that directly target the immune system. This substance effectively treats psoriasis by inhibiting protein and T cell activity that the immune system stimulates when mistakenly acting as if the body is under attack. As a result, overproduction of skin cells rapidly generates those silvery, scaly psoriasis lesions indicative of psoriasis. These "plaques" are comprised of thousands of dead skin cells, which the skin is unable to shed normally.
While researchers do not have all the solutions yet, the answer to the question is psoriasis heredity points to a definite yes. However, variables affecting the heritable factor may eventually provide the knowledge necessary to defeat this debilitating condition.