Initial symptoms in infants and toddlers may include:
- Developmental delay
- Emotional and behavior problems
- Ectopia lentis (dislocation of the ocular lens) or severe myopia (nearsightedness)
- Marfanoid habitus: tall/ thin build; long fingers, arms, and legs
- Genu valgum, pes cavus
- Malar flush
- Decreased hair, skin, iris pigmentation
- Vascular disease and stroke
- Psychiatric abnormalities
- Mental retardation
- Contact the family and evaluate the infant for poor feeding or other problems.
- Urgent treatment is not likely to be needed in the newborn period, but patients should be referred immediately (see the ACT Sheet for Homocystinuria (ACMG) ( 347 KB) for additional information).
- To confirm the diagnosis, work with the following service(s): we currently have no Newborn Screening Programs service providers listed, please search our Services database for related services.
- For evaluation and ongoing collaborative management, consult the following service(s): we currently have no Pediatric Genetics service providers listed, please search our Services database for related services.
- Educate the family regarding signs, symptoms, and the need for urgent care when the infant becomes ill (see Homocystinuria - Information for Parents (STAR-G)).
- Assist in implementation and maintenance of a diet low in methionine and proteins; baby aspirin is also recommended starting in late teenager years.
- Provision of vitamin B6, betaine, vitamin B12, and methylfolate may be indicated.
- Regular blood and urine tests to monitor amino acid levels and diet may be indicated.
- For those identified after irreversible consequences, assist in management, particularly with developmental and educational interventions.
Homocystinuria - Information for Professionals (STAR-G)
Contains a structured list of information about homocystinuria; Screening, Technology, and Research in Genetics.
Excellent review that includes a clinical description and information about differential diagnoses, management, genetic counseling, and molecular genetics; sponsored by the National Center for Biotechnology Information (NCBI).
Homocystinuria Resources (NLM)
Comprehensive compilation of links to information, articles, research, case studies, genetics, and more; National Library of Medicine and the Genetic Alliance.
Extensive literature review organized by description, clinical features, genetics, diagnosis, differential diagnosis, management, nomenclature, history, and animal models; Online Mendelian Inheritance in Man.
Utah Newborn Screening Program (UDOH)
Provides information about the program, related legislation, training for practices, and newborn conditions; Utah Department of Health.
Genetics in Primary Care Institute (AAP)
The goal of this site is to increase collaboration in the care of children with known or suspected genetic disorders. It includes health supervision guidelines and other useful resources; represents a collaboration among the Health Resources & Services Administration, the Maternal and Child Health Bureau, and the American Academy of Pediatrics.
Homocystinuria - Information for Parents (STAR-G)
A fact sheet, written by a genetic counselor and reviewed by metabolic and genetic specialists, for families who have received an initial diagnosis of this newborn disorder; Screening, Technology and Research in Genetics.
Homocystinuria (Genetics Home Reference)
Excellent, detailed review for patients and families affected by homocystinuria; a service of the U.S. National Library of Medicine.
ACT Sheet for Homocystinuria (ACMG) ( 347 KB)
Contains short-term recommendations for clinical follow-up of the newborn who has screened positive; American College of Medical Genetics.
We currently have no Newborn Screening Programs service providers listed; search our Services database for related services.
We currently have no Pediatric Genetics service providers listed; search our Services database for related services.
For other services related to this condition, browse our Services categories or search our database.
Hypermethioninemias of genetic and non-genetic origin: A review.
Am J Med Genet C Semin Med Genet. 2011;157(1):3-32. PubMed abstract
Discusses briefly the genetic and non-genetic conditions that sometimes lead to abnormally elevated methionine. Focuses on recent developments and differential diagnosis of hypermethioninemia.