SNP Shot: Genomic Insights

Galactosialidosis is a disorder affecting multiple parts of the body. It exists in three forms, each defined by the age of symptom onset and the specific symptoms present.

The early infantile form of galactosialidosis is characterized by significant swelling due to fluid buildup before birth (hydrops fetalis), a noticeable bulge in the lower abdomen (inguinal hernia), and enlargement of the liver and spleen (hepatosplenomegaly). Other signs include abnormal bone development (dysostosis multiplex) and distinct facial characteristics often described as "coarse." Some infants may also experience heart enlargement (cardiomegaly), a cherry-red spot in the eye detectable during examination, and kidney disease that can worsen to kidney failure. Diagnosis typically occurs between birth and 3 months, and survival usually extends into late infancy.

The late infantile form of galactosialidosis shares some similarities with the early infantile form, but the signs and symptoms are less severe and appear later in infancy. Key features include short stature, dysostosis multiplex, heart valve issues, hepatosplenomegaly, and "coarse" facial features. Additional symptoms observed in some individuals include intellectual disability, hearing loss, and a cherry-red spot. Symptoms usually begin within the first year of life. Life expectancy varies depending on the severity of the symptoms.

The juvenile/adult form of galactosialidosis presents with signs and symptoms that differ from the other two forms. It is marked by problems with coordination (ataxia), muscle spasms (myoclonus), seizures, and a gradual decline in intellectual abilities. Individuals often develop dark red spots on the skin (angiokeratomas), spinal bone abnormalities, "coarse" facial features, a cherry-red spot, vision loss, and hearing loss. The onset of symptoms varies widely, with an average age of 16. This form generally does not affect life expectancy.

Inheritance:

Galactosialidosis is inherited through an autosomal recessive pattern. This means that both copies of the responsible gene in each cell must have mutations for the condition to manifest. Individuals with autosomal recessive conditions inherit one mutated copy of the gene from each parent, who are carriers but usually show no signs or symptoms of the disorder.