(I) Methylmalonic acidemia (cblC) (II) Homocystinuria (HCY)

(I) Methylmalonic acidemia is an inherited disorder in which the body is unable to process certain proteins and fats (lipids) properly. (II) Homocystinuria is an inherited disorder in which the body is unable to process certain building blocks of proteins (amino acids) properly.

(I) Effects of the disorder, which normally arise during infancy, range from mild to life-threatening. Symptoms include vomiting, dehydration, weak muscle tone, developmental delay, lethargy, enlarged liver, failure to thrive. Long-term complications can lead to intellectual disability, kidney disease, and pancreatitis and can lead to coma or death. This disorder may also arise due to mutations in the MMADHC, MCEE, MUT, MMAA, and MMAB genes. (II) Multiple forms of this disorder exist but most common symptoms include nearsightedness, dislocation of the lens at the front of the eye, increased risk of abnormal blood clotting, and brittle bones. Although most often mutations in the CBS gene cause this disorder, it may also arise from mutations in the MMADHC, CBS, MTHFR, MTR, and MTRR.