Rhizomelic Chondrodysplasia Punctata (RCDP)
Description
Rhizomelic Chondrodysplasia Punctata (RCDP) is a rare genetic disorder that affects bone growth and development, leading to a variety of physical challenges. This comprehensive guide provides detailed information about RCDP, including its causes, symptoms, diagnosis, management, and resources for families. Learn how to recognize the signs, understand the inheritance patterns, and find support for individuals with RCDP.
Genes Involved
RCDP is caused by mutations in one of three genes:
- RCDP1 (PEX7): The most common type of RCDP.
- RCDP2 (PEX1): A less common type of RCDP.
- RCDP3 (PEX6): The rarest type of RCDP.
Recognizing the Signs and Symptoms
RCDP is characterized by a range of symptoms, including:
- Short limbs: The arms and legs are disproportionately short, with the upper arms and thighs being particularly affected (rhizomelia).
- Dwarfism: Individuals with RCDP are typically of short stature.
- Joint stiffness and contractures: Limited range of motion in joints, often affecting elbows, knees, and hips.
- Distinctive facial features: A flat nasal bridge, prominent forehead, and small chin are common.
- Eye abnormalities: Cataracts, glaucoma, or other eye problems.
- Skeletal abnormalities: Abnormalities in the ribs, spine, and skull.
- Skin problems: Dry, scaly skin, and sometimes, areas of thickened skin.
- Respiratory problems: Difficulty breathing due to small chest size or weak respiratory muscles.
- Neurological problems: Seizures, developmental delays, and intellectual disability may occur in some cases.
- Other complications: Hearing loss, heart defects, and kidney problems are also possible.
Causes
RCDP is caused by mutations in genes that are responsible for the production of enzymes involved in a process called peroxisome biogenesis. Peroxisomes are small organelles within cells that play a crucial role in breaking down fats and other substances. Mutations in these genes lead to a deficiency in these enzymes, disrupting the proper functioning of peroxisomes and causing the characteristic features of RCDP.
Inheritance/recurrence risk
RCDP is usually inherited in an autosomal recessive pattern. This means that both parents must carry a copy of the mutated gene for their child to inherit the disorder. If both parents are carriers, there is a 25% chance that their child will have RCDP, a 50% chance that their child will be a carrier, and a 25% chance that their child will not inherit the disorder.
