SUMMARY
Homocystinuria is a rare condition that affects amino acid levels in the body. In particular, it affects an amino acid called homocysteine. In children with this disorder, levels of homocysteine in the blood and urine are higher than normal. This may be caused by:
- A genetic mutation
- A vitamin deficiency
High homocysteine levels can lead to increased risk for:
- Stroke
- Heart attack
- Blood clots
The genetic form of the disorder is associated with:
- Dislocation of the lens of the eyes
- Eyesight—specifically, nearsightedness
- Developmental delays and learning/intellectual disabilities
- Tall stature
- Long fingers
- Difficulty in gaining weight, such as “failure to thrive”
- Weak bones (osteoporosis)
- Curvature of the spine (scoliosis)
- Caved-in chest (pectus excavatum)
Treatment depends on the underlying cause, but can include:
- Restricting certain types of protein in the diet
- Taking vitamins
- Sometimes, a medication called betaine
SIGNS AND SYMPTOMS
The signs and symptoms of homocystinuria can begin in childhood or adolescence. They are due to the effects of high homocysteine levels on different tissues in the body.
The classic form of the disorder can lead to symptoms in all different parts of the body:
Neurologic
Skin
Musculoskeletal
This disorder can affect the muscles, joints and bones. Many children with this disorder have a specific set of features called Marfanoid features. Muscle, joint, and bone differences can include:
- Brittle bones (osteoporosis)
- Caved-in chest (pectus excavatum)
- Curvature of the spine (scoliosis)
- Long, thin limbs and fingers
- Knock knees (genu valgum)
- Highly arched feet
Eyes
TREATMENT AND THERAPIES
Types of treatment can vary based on how severe the disease is and on other factors.
Treatments include:
Protein-restricted diet
Vitamin supplementation
Medication
Resources
HCU Network America
The mission of HCU Network America is to help patients with Homocystinuria and related disorders manage their disease and to find a cure. HCU Network America provides resources and information which includes: finding a clinic, guidelines for diagnosis and management, tool kits and a checklist, as well as videos. The website has an extensive research section which highlights grants, the organization’s projects, and publications. One of the goals of HCU Network American is to create connections across the community and facilitate sharing of information and best practices through in-person and virtual events and discussions. Another key goal is to improve newborn screening for HCU. An online survey is accessible on the website to build support for improving that process. The Homocystinuria Awareness and Support private Facebook group is hosted by HCU Network America.
HCU Network Australia
HCU Network Australia’s vision is to be a driving force in the journey to a cure for Homocystinuria, improving quality of life along the way. They provide community and resource news updates, educational resources and support, and drives research for improved outcomes for those impacted by homocystinuria. HCU Network Australia also hosts a private Facebook group for Australian patients and caregivers with over 50 members.
Child Neurology Foundation (CNF) solicits resources from the community to be included on this webpage through an application process. CNF reserves the right to remove entities at any time if information is deemed inappropriate or inconsistent with the mission, vision, and values of CNF.