Zellweger Spectrum Disorder
Description
Zellweger Spectrum Disorder (ZSD) is a group of rare, inherited disorders that affect the brain, liver, and other organs. These conditions are caused by mutations in genes responsible for peroxisome biogenesis, a process essential for breaking down fats and producing certain essential molecules. Zellweger Spectrum Disorder is a serious and often fatal condition, but early diagnosis and management can improve quality of life for those affected.
Genes Involved
Zellweger Spectrum Disorder is caused by mutations in genes involved in peroxisome biogenesis. These genes include:
- PEX1
- PEX2
- PEX3
- PEX5
- PEX6
- PEX7
- PEX10
- PEX12
- PEX13
- PEX14
- PEX16
- PEX19
- PEX26
- PEX30
- PEX31
- PEX32
- PEX35
- PEX36
Recognizing the Signs and Symptoms
Zellweger Spectrum Disorder presents with a range of symptoms, often appearing at birth or within the first few months of life. These can include:
- Brain abnormalities: Seizures, developmental delays, hypotonia (low muscle tone), and impaired reflexes.
- Liver dysfunction: Enlarged liver, jaundice (yellowing of the skin and eyes), and elevated liver enzymes.
- Eye abnormalities: Retinopathy (damage to the retina) and cataracts.
- Skeletal problems: Dysmorphic features, such as a flattened face, large fontanelles (soft spots in the skull), and short limbs.
- Other issues: Feeding difficulties, breathing problems, and heart defects.
Causes
Zellweger Spectrum Disorder is caused by mutations in genes involved in peroxisome biogenesis. Peroxisomes are small organelles within cells that play a critical role in breaking down fats and producing essential molecules. Mutations in these genes prevent the proper formation of peroxisomes, leading to a buildup of harmful substances in the body.
Inheritance/recurrence risk
Zellweger Spectrum Disorder is inherited in an autosomal recessive pattern. This means that both parents must carry a copy of the mutated gene for their child to be affected. If both parents are carriers, there is a 25% chance with each pregnancy that their child will inherit the condition. It is important for families with a history of Zellweger Spectrum Disorder to discuss genetic counseling and testing with their healthcare providers.
