Biomedical subjects

Alfred E Slonim

Publications and source records attributed to Alfred E Slonim.

4 recordsLinked to original sources

PubMed2007

Modification of the natural history of adult-onset acid maltase deficiency by nutrition and exercise therapy.

Adult-onset acid maltase deficiency is an inherited lysosomal skeletal-muscle disease characterized by progressive myopathy and respiratory failure, for which there is no known therapy. In an uncontrolled, prospective study, we evaluated whether adherence to high-protein and low-carbohydrate nutrition and exercise therapy (NET) can slow the progressive deterioration of muscle function in this disease. Thirty-four patients have been treated with NET for periods of 2-10 years (mean 4.5 +/- 2.5). Pre-NET rate of muscle function deterioration, as measured by the Walton scale, was compared to post-NET rate. Twenty-six patients were deemed to be consistently compliant with NET. Difference between pre-NET slope of muscle function deterioration to that of post-NET slope in compliant patients was -0.29 (95% CI -0.19, 0.39) (P < 0.0001). We conclude that compliance with NET can slow deterioration of muscle function and improve the natural history of adult-onset acid maltase deficiency. Muscle Nerve, 2006.

Adult↗

PubMed2006

Benign course of glycogen storage disease type IIb in two brothers: nature or nurture?

Two brothers with the childhood variant of type II glycogenosis (GSD-IIb) treated with nutrition and exercise therapy (NET) from a young age showed an unusually benign course. Muscle biopsy from the older brother, which showed characteristic vacuolar glycogen accumulation at age 2, had reverted to normal by age 16. A muscle biopsy from the younger brother was normal at 5 years. It is uncertain whether this anomalous evolution was spontaneous (nature) or due to the symptomatic therapy (nurture), but NET should be considered in patients with GSD-IIb until enzyme replacement or gene therapy become generally available.

DNA↗

PubMed2005

Epimerase-deficiency galactosemia is not a binary condition.

Epimerase-deficiency galactosemia results from the impairment of UDP-galactose 4'-epimerase (GALE), the third enzyme in the Leloir pathway of galactose metabolism. Originally identified as a clinically benign "peripheral" condition with enzyme impairment restricted to circulating blood cells, GALE deficiency was later demonstrated also to exist in a rare but clinically severe "generalized" form, with enzyme impairment affecting a range of tissues. Isolated cases of clinically and/or biochemically intermediate cases of epimerase deficiency have also been reported. We report here studies of 10 patients who, in the neonatal period, received the diagnosis of hemolysate epimerase deficiency. We have characterized these patients with regard to three parameters: (1) GALE activity in transformed lymphoblasts, representing a "nonperipheral" tissue, (2) metabolic sensitivity of those lymphoblasts to galactose challenge in culture, and (3) evidence of normal versus abnormal galactose metabolism in the patients themselves. Our results demonstrate two important points. First, whereas some of the patients studied exhibited near-normal levels of GALE activity in lymphoblasts, consistent with a diagnosis of peripheral epimerase deficiency, many did not. We detected a spectrum of GALE activity levels ranging from 15%-64% of control levels, demonstrating that epimerase deficiency is not a binary condition; it is a continuum disorder. Second, lymphoblasts demonstrating the most severe reduction in GALE activity also demonstrated abnormal metabolite levels in the presence of external galactose and, in some cases, also in the absence of galactose. These abnormalities included elevated galactose-1P, elevated UDP-galactose, and deficient UDP-glucose. Moreover, some of the patients themselves also demonstrated metabolic abnormalities, both on and off galactose-restricted diet. Long-term follow-up studies of these and other patients will be required to elucidate the clinical significance of these biochemical abnormalities and the potential impact of dietary intervention on outcome.

Base Sequence↗

PubMed2005

Biotinidase deficiency: novel mutations and their biochemical and clinical correlates.

Biotinidase deficiency is a defect in the recycling of the vitamin biotin. Biotin supplementation can markedly improve the neurological and cutaneous symptoms of affected children and prevent symptoms in children identified by newborn screening or treated since birth. We have determined thirteen novel mutations in children with the disorder. Two nonsense mutations, eight single missense mutations, three allelic double missense mutations, and two are polymorphisms were identified in the biotinidase gene (BTD). One of the missense mutations, c.734G>A (p. C245Y), is the first to be reported that alters the cysteine in the putative location crucial for ester formation and binding of the biotinyl-moiety in the active site of the enzyme. These mutations add to the growing list of mutations that are helping to delineate structure/function relationships of the enzyme.

Alleles↗