Steps 4) What treatments are available?
There is no cure for Homocystinuria at this time, but treatment is available that may be able to keep the disease under control and avoid or lessen symptoms. Treatment should be started from the time of diagnoses and continued for life. Your treatment will vary greatly depending on your specific diagnosis, your amount of active enzyme, your age, height, activity level, your other health issues, and your metabolic rate. Because many factors can play into your homocysteine and methionine levels, it is important that you follow up with your metabolic specialist or geneticist on a regular basis (they will decide how often is right for you).
CBS Deficient Homocystinuria Treatments
The guidelines recommend patients with CBS deficient Homocystinuria who are responsive to pyridoxine to achieve tHCY under 50 µmol/L, and for those who are unresponsive to pyridoxine to achieve tHCY levels under 100 µmol/L. Some clinicians aim for lower levels.
About half of the CBS deficient Homocystinuria population is responsive to pyridoxine or Vitamin B6. These patients can supplement only B6 and may achieve target levels of tHcy and avoid symptoms. Although there are some fully responsive patients, many responsive patients are partial responders and will require additional treatments.
The remaining patients are not B6 responsive. These patients will need a combination of therapies.
Dietary restriction of protein is recommended if target tHcy levels are not achieved with pyridoxine supplementation. The amount of protein recommended depends upon the amount of active enzyme patients have and their response to therapies. For those on a low protein diet, there are special low protein foods such as pasta and bread that a patient can consume. In addition to food, the patient will need to supplement with a dietary metabolic formula. This special formula will give them all the essential nutrients their body needs, including the other essential amino acids they lack due to the low protein diet. This formula is methionine free and often ordered especially for the patient.
Vitamin B12 and folate are also usually recommended. For those who do not achieve targets with diet alone, a medication called Cystadane is added (also known as Betaine Anhydrous, and Trimethylglycine ((TMG)), which helps to metabolize some of the homocysteine.
Patients with severe MTHFR are treated with the medication Betaine (Cystadane ®). Some will be supplemented with folate (or folinic acid), vitamin B12, and other vitamins. Different metabolic/genetic clinics have different approaches to diet. If you want to read more (warning this is a copy of the document your medical professional will use so it is long and technical), the guidelines for management and diagnosis are: here
Cobalamin Defect Treatments
Therapies for the cobalamin disorders focus on reducing homocysteine with betaine (Cystadane ®). Many will need hydroxycobalamin (injection into the muscle in the leg or arm). Sometimes individuals will be given folate or levocarnitine as well.