Saccharopinuria (an excess of
saccharopine in the urine), also called saccharopinemia, saccharopine dehydrogenase deficiency or alpha-aminoadipic semialdehyde synthase deficiency,
is a variant form of
hyperlysinemia
Hyperlysinemia is an autosomal recessive metabolic disorder characterized by an abnormal increase of lysine in the blood, but appears to be benign. It is caused by mutations in '' AASS'', which encodes α-aminoadipic semialdehyde synthase.
Hype ...
.
It is caused by a partial deficiency of the
enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...
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. Lysine contains an α-amino group (which is in the protonated form when the lysine is dissolved in water at physiological pH), an α-carboxylic acid group ( ...
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 autosome ...
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 and ...
, but this cannot be established as individuals affected by saccharopinuria typically have only a 40% reduction in functional enzyme.
[
]
See also
* Hyperlysinemia
Hyperlysinemia is an autosomal recessive metabolic disorder characterized by an abnormal increase of lysine in the blood, but appears to be benign. It is caused by mutations in '' AASS'', which encodes α-aminoadipic semialdehyde synthase.
Hype ...
References
External links
*
Amino acid metabolism disorders
Rare diseases
{{genetic-disorder-stub