Bitterness of Glucose/Galactose

Abstract

Glucose galactose malabsorption (GGM) is a rare autosomal recessive disorder characterized by life-threatening osmotic diarrhea at infancy. When the intake of the offending sugars (namely, glucose, galactose and lactose) is ceased, the diarrhea promptly stops. Mutations in the SLC5A1 gene, encoding the sodium-glucose co-transporter located in the brush border of enterocytes, have been shown to cause the disease. More than 300 subjects of diverse origin have been reported worldwide, most of whom are a result of a consanguineous union. We examined 6 patients from 4 families presenting with complaints consistent with GGM and responsive to the appropriate fructose-based diet. Genomic DNA of the patients was polymerase chain reaction amplified for each of the 15 exons of the SLC5A1 gene and analyzed by nucleotide sequencing. The analysis lead to the identification of 2 novel mutations: a 1915 del C mutation, a frameshift mutation leading to a premature stop at codon 645; and a substitution missense mutation of T to C on nucleotide 947 (exon 9) causing a L316P substitution. In addition, G426R and C255W mutations previously described were identified; in both cases, the patients were shown to be homozygous and their parents heterozygous for the mutation. Of note, additional patients who underwent a similar evaluation at our center for suspected GGM did not show mutations in the SLC5A1 gene. Because the latter did not previously undergo a diagnostic algorithm in full, for instance, one that may consist of a glucose breath hydrogen test and an empiric attempt of a dietary switch to galactomin, we suggest that molecular genotyping of such patients should only follow such appropriate clinical evaluation.

Nutrition management of congenital glucose–galactose malabsorption

“…However, because glucose and galactose cannot be absorbed in CGGM children, the large amount of unabsorbed water, electrolytes, and glucose that passes through the small intestine into the colon exceeds the absorption capacity of the intestinal tract and thus results in severe watery diarrhea. [4,15] The feces of the CGGM patients are acidic and contain a large amount of glucose, resulting in malnutrition and even death. However, the symptoms of abdominal distention, vomiting, and anorexia are usually uncommon.…”

“…To date, >40 SLC5A1 mutations have been identified in CGGM patients. [2,3] Additionally, CGGM is extremely rare and only approximately 300 cases have been reported worldwide [4] . The incidence of CGGM varies in different populations, and consanguineous correlations are evident in some areas, which confirms the autosomal recessive heredity pattern of CGGM.…”

“…The incidence of CGGM varies in different populations, and consanguineous correlations are evident in some areas, which confirms the autosomal recessive heredity pattern of CGGM. [2,3,4,5] There is no specific therapy for CGGM, and the most effective treatment is long-term special dietary therapy that avoids foods containing glucose and galactose. [3,5,6] However, maintaining normal physical and neurological development of CGGM children is still very challenging, especially the long-term nutrition management.…”

SLC5A1 Mutations in Saudi Arabian Patients With Congenital Glucose‐Galactose Malabsorption

“…cGGM is quite a rare disease and upon review of the literature available on this disorder, we estimate that there are approximately 300 patients known worldwide. Because of the overall rare occurrence, incidence differs in various populations with some increase in certain regions with higher rates of consanguinity (4,5,9–12), which supports the autosomal recessive mode of inheritance for cGGM.…”

Novel Mutation in the SLC5A1 Gene Causing Glucose-Galactose Malabsorption: First Confirmed Case From Central America

“…The diagnosis can be made clinically based on the presence of diarrhea soon after birth, evidence of carbohydrate malabsorption in the stool, and resolution of diarrhea with dietary elimination of glucose and galactose. Molecular confirmation of mutations in the SLC5A1 gene can be obtained ( 7 ). The hydrogen breath test can also be used, though is less practical in infants ( 4 ).…”