SNP Shot: Genomic Insights

Hermansky-Pudlak syndrome (HPS) is a genetic condition primarily defined by oculocutaneous albinism, resulting in unusually light pigmentation of the skin, hair, and eyes. Those affected often present with fair skin and light-colored hair. Due to reduced pigment, individuals with HPS are at increased risk for sun-related skin damage and skin cancer. Oculocutaneous albinism in HPS impacts the iris and retina, leading to vision impairment. Common vision issues include reduced eyesight, involuntary rapid eye movements (nystagmus), and heightened light sensitivity (photophobia). Typically, these vision problems stabilize after early childhood.

Individuals with HPS also experience issues with blood clotting (coagulation defects), leading to easy bruising and prolonged bleeding.

Pulmonary fibrosis, a lung disease characterized by scar tissue formation, can develop in some people with HPS, causing breathing difficulties. Symptoms usually manifest in their early thirties and worsen quickly. Sadly, those who develop pulmonary fibrosis often survive less than ten years after the onset of breathing problems.

Less frequent complications of HPS include inflammation of the large intestine (granulomatous colitis) and kidney failure.

HPS comprises nine distinct types, differentiated by specific symptoms, signs, and the underlying genetic mutation. Types 1 and 4 represent the most severe forms. Pulmonary fibrosis is only associated with types 1, 2, and 4. Types 3, 5, and 6 exhibit the mildest symptoms. Information regarding the characteristics and severity of types 7, 8, and 9 remains limited.

Inheritance:

HPS follows an autosomal recessive inheritance pattern. This means that both copies of the responsible gene in each cell must carry a mutation for the condition to manifest. Parents of an individual with HPS each carry one copy of the mutated gene but generally do not exhibit any signs or symptoms themselves.