Saccharopinuria (an excess of
saccharopine
Saccharopine is an intermediate in the metabolism of amino acid lysine. It is a precursor of lysine in the alpha-aminoadipate pathway which occurs in fungi and euglenids. In mammals and higher plants saccharopine is an intermediate in the degrada ...
in the urine), also called saccharopinemia, saccharopine dehydrogenase deficiency or alpha-aminoadipic semialdehyde synthase deficiency,
is a variant form of
hyperlysinemia.
It is caused by a partial deficiency of the
enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...
saccharopine dehydrogenase, which plays a secondary role in the
lysine
Lysine (symbol Lys or K) is an α-amino acid that is a precursor to many proteins. It contains an α-amino group (which is in the protonated form under biological conditions), an α-carboxylic acid group (which is in the deprotonated − ...
metabolic pathway. Inheritance is thought to be
autosomal
An autosome is any chromosome that is not a sex chromosome. The members of an autosome pair in a diploid cell have the same morphology, unlike those in allosomal (sex chromosome) pairs, which may have different structures. The DNA in autosom ...
recessive
In genetics, dominance is the phenomenon of one variant ( allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant an ...
, but this cannot be established as individuals affected by saccharopinuria typically have only a 40% reduction in functional enzyme.
[
]
See also
* Hyperlysinemia
References
External links
*
Amino acid metabolism disorders
Rare diseases
{{genetic-disorder-stub