The disorders of intracellular cobalamin metabolism that are inherited in an autosomal recessive manner result from the deficient synthesis of AdoCbl and MeCbl derived from Vitamin B12; the types of disorders includes: cblA, cblB, cblC, cblD, etc., depending on the pathogenic genes., The cblD disease (MIM# 277410) caused by mutations in the MMADHC gene contains three subtypes: cblD-isolated methylmalonic acidemia (MMA), cblD-isolated homocystinuria (HC) and cblD-MMA/HC (combined MMA and HC). We herein reported the Chinese patient with cblD disease attributable to a novel MMADHC mutation related to translation reinitiation.
Loci and nature of the mutations in MMADHC determine the subtype of cblD disease. Mutation c.24-25delAG at the 5' end of the MMADHC coding sequence is a frameshift mutation that can produce premature termination codons.
Previously reported manifestations of cblD disease included developmental delay, dystonia, epilepsy, seizures, hyperammonemia, metabolic dysequilibrium, etc. The patient in this study was similar to one patient in the report of Miousse et al .; both of patients were admitted to hospital due to vomiting and suffered from metabolic acidosis before the diagnosis of cblD disease, and they were both responsive to Vitamin B12.
Guidelines for diagnosis and management of the cobalamin-related remethylation disorders cblC, cblD
, cblE, cblF, cblG, cblJ and MTHFR deficiency.
Plasma amino acids were also within reference intervals, excluding a combined disorder of cobalamin and homocysteine metabolism, such as cblC, cblD
, or cblF types.
"The acquisition of DLD enhances our position as a Midwest Integrated Communications Provider by expanding our reach into the rapidly growing mid-South region," said CBLD President Barry Nelson.
CBLD plans to convert DLD's headquarters into a regional sales and service office and roughly double its staff, making the office similar in size and capability to CBLD's other regional offices.
CBLD is a full-service communications company, providing complete integrated packages of voice, data, and Internet communications services to businesses in the Midwest.
Internet Services - CBLD
entered into a strategic relationship with PSINet to provide CBLD-brand high speed and dial-up Internet access to its customers outside of Cincinnati.
4 Human genes: CBS, cystathionine-beta-synthase; MTRR, 5-methyltetrahydrofolate-homocysteine methyltransferase reductase; MTR, 5-methyltetrahydrofolate-homocysteine methyltransferase; MMACHC, methylmalonic aciduria (cobalamin deficiency) cblC type, with homocystinuria; MMADHC, methylmalonic aciduria (cobalamin deficiency) cblD
type, with homocystinuria; LMBRD1, LMBR1 domain containing 1; FBN1, fibrillin 1.