In the fungus Neurospora crassa, crosses made between normal sequence strains and some translocation strains can yield three kinds of progeny: normal sequence (like one parent), translocation sequence (like the other parent) and a novel class that is duplicated for the translocated segment. The duplication progeny arise when one component of the translocation segregates with a normal sequence c...

The term “organic acidemia” or “organic aciduria” (OA) applies to inborn errors of metabolism (IEM) in which organic acids accumulate in tissues and biological fluids. Classical organic acidurias include methylmalonic aciduria (MMA), propionic aciduria (PA), isovaleric aciduria (IVA) and maple syrup urine disease (MSUD). Aminoacidurias like phenylketonuria are common in the western population. ...

In the filamentous fungus Neurospora crassa, cross walls between individual cells are normally incomplete, making the entire fungal network vulnerable to attack by viruses and selfish DNAs. Accordingly, several genome surveillance mechanisms are maintained to help the fungus combat these repetitive elements. One of these defense mechanisms is called meiotic silencing by unpaired DNA (MSUD), whi...

Dihydrolipoamide dehydrogenase deficiency, also known as maple syrup urine disease (MSUD) type III, is caused by the deficiency of the E3 subunit of branched chain alpha-ketoacid dehydrogenase (BCKDH), α-ketoglutarate dehydrogenase (αKGDH), and pyruvate dehydrogenase (PDH). DLD deficiency variably presents with either a severe neonatal encephalopathic phenotype or a primarily hepatic phenotype....

In Neurospora, a gene present in an abnormal number of copies is usually a red flag for mischief. One way to deal with these potential intruders is by destroying their transcripts. Widely known as RNA interference (RNAi), this mechanism depends on the "dicing" of a double-stranded RNA intermediate into small-interfering RNA, which in turn guide the degradation of mRNA from the target gene. Quel...

In treatment of metabolic imbalances caused by maple syrup urine disease (MSUD), peritoneal dialysis, and hemofiltration, pharmacological treatments for elimination of toxic metabolites can be used in addition to basic dietary modifications. Therapy with sodium phenylacetate/benzoate or sodium phenylbutyrate (NaPB) in urea-cycle disorder cases has been associated with a reduction in branched-ch...

A Japanese Black calf, 3 day-old male, showed severe ataxia, lateral recumbency, and opisthotonos at the birth. Histopathological examinations revealed severe status spongiosis throughout the central nervous system. Numerous vacuoles within the neuropile varying in size and shape were observed in both formalin-fixed paraffin and cryostat sections. In the lesions, a limited number of spheroids a...

2-Keto-3-methylvaleric acid (KMVA) has been found not to undergo spontaneous keto-enol tautomerization in neutral aqueous solution, alone or in the presence of large concentrations of pyridoxamine or pyridoxamine-5-phosphate. This finding denies the commonly held suppositions that 3R-KMVA is derived spontaneously from 3S-KMVA in vivo, and that L-alloisoleucine is the product of the reamination ...

Maple syrup urine disease (MSUD), an autosomal recessive inborn error of metabolism due to defects in the branched-chain α-ketoacid dehydrogenase (BCKD) complex, is commonly observed among other inherited metabolic disorders in the kingdom of Saudi Arabia. This report presents the results of mutation analysis of three of the four genes encoding the BCKD complex in 52 biochemically diagnosed MSU...

Seizures are a common presenting manifestation in children with disorders of amino acid metabolism. However, seizures may be very common in some specific diseases, but are rare in other diseases. In patients with classical maple syrup urine disease (MSUD), seizures commonly occur in the neonatal stage. But in intermittent or intermediate MSUD, seizures may develop in a later stage, or are uncom...