Dietary management for pyridoxine-dependent epilepsy due to α-aminoadipic semialdehyde dehydrogenase deficiency, a follow-on from the international consortium guidelines.

Pyridoxine-dependent epilepsy (PDE-ALDH7A1) is a neurometabolic disorder in the lysine metabolism pathway. In 2014 and 2021, the International PDE consortium published consensus guidelines about diagnosis and management. In this follow-on, a literature review was performed and nutrition management was evaluated through an international dietary questionnaire with 40 respondents. This manuscript discusses consensus dietary statements and the practical provision of lysine reduction therapies. Results from the questionnaire, statements from the PDE consensus guidelines, new data from the literature, as well as clinical practice experience of the metabolic dietitian group form the basis of these updated practical diet recommendations. These dietary management recommendations can support dietitians, nutritionists, and physicians in initiation and monitoring of lysine reduction therapies for PDE-ALDH7A1 patients and families.

Inconsistencies in the Nutrition Management of Glutaric Aciduria Type 1: An International Survey.

Glutaric aciduria type 1 (GA-1) is a cerebral organic aciduria characterized by striatal injury and progressive movement disorder. Nutrition management shifted from a general restriction of intact protein to targeted restriction of lysine and tryptophan. Recent guidelines advocate for a low-lysine diet using lysine-free, tryptophan-reduced medical foods. GA-1 guideline recommendations for dietary management of patients over the age of six are unclear, ranging from avoiding excessive intake of intact protein to counting milligrams of lysine intake. A 22-question survey on the nutrition management of GA-1 was developed with the goal of understanding approaches to diet management for patients identified by newborn screening under age six years compared to management after diet liberalization, as well as to gain insight into how clinicians define diet liberalization. Seventy-six responses (25% of possible responses) to the survey were received. Nutrition management with GA-1 is divergent among surveyed clinicians. There was congruency among survey responses to the guidelines, but there is still uncertainty about how to counsel patients on diet optimization and when diet liberalization should occur. Ongoing clinical research and better understanding of the natural history of this disease will help establish stronger recommendations from which clinicians can best counsel families.

Impact on Isoleucine and Valine Supplementation When Decreasing Use of Medical Food in the Nutritional Management of Methylmalonic Acidemia.

BACKGROUND: Methylmalonic acidemia (MMA) is an autosomal recessive disorder treated with precursor-free medical food while limiting natural protein. This retrospective chart review was to determine if there was a relationship between medical food, valine (VAL) and/or isoleucine (ILE) supplementation, total protein intake, and plasma amino acid profiles. Methods: A chart review, of patients aged 31 days or older with MMA treated with dietary intervention and supplementation of VAL and/or ILE and followed at the Children's Hospital Colorado Inherited Metabolic Diseases Clinic. Dietary prescriptions and plasma amino acid concentrations were obtained at multiple time points. RESULTS: Baseline mean total protein intake for five patients was 198% of Recommended Dietary Allowance (RDA) with 107% natural protein and 91% medical food. Following intervention, total protein intake (p = 0.0357), protein from medical food (p = 0.0142), and leucine (LEU) from medical food (p = 0.0276) were lower, with no significant change in natural protein intake (p = 0.2036). At baseline, 80% of patients received VAL supplementation and 100% received ILE supplementation. After intervention, only one of the cohort remained on supplementation. There was no statistically significant difference in plasma propiogenic amino acid concentrations. CONCLUSIONS: Decreased intake of LEU from medical food allowed for discontinuation of amino acid supplementation, while meeting the RDA for protein.