Alpha-ketoadipic aciduria: degradation studies with fibroblasts,.

Area of Science:

• Biochemistry
• Metabolic Disorders
• Genetics

Background:

• Alpha-ketoadipic aciduria is a rare metabolic disorder.
• Identifying the precise metabolic defect is crucial for understanding and potentially treating the condition.

Purpose of the Study:

• To investigate the metabolic defect in a patient with alpha-ketoadipic aciduria.
• To localize the metabolic pathway affected by the disorder using radiolabeled lysine metabolites.

Main Methods:

• Degradation studies were performed using radiolabeled lysine metabolites (alpha-D,L-(1-14-C) aminoadipate, alpha-(1-14-C) ketoadipate, and (1,5-14-C) glutarate).
• Fibroblast cultures from the patient and normal controls were used.
• Amniotic fluid cells from early gestation were also analyzed.

Main Results:

• Fibroblasts from the patient showed significantly reduced 14-CO-2 production from alpha-D,L-(1-14-C) aminoadipate and alpha-(1-14-C) ketoadipate compared to normal controls.
• 14-CO-2 production from (1,5-14-C) glutarate was within the normal range.
• Early-gestation amniotic fluid cells demonstrated similar alpha-(1-14-C) ketoadipate degradation activity to postnatal fibroblasts.

Conclusions:

• The findings strongly suggest a defect in the oxidative decarboxylation of alpha-ketoadipate as the cause of alpha-ketoadipic aciduria.
• This defect can be identified and potentially diagnosed using cultured cells from early pregnancy.