Importance of genetic sequencing studies in managing chronic neonatal diarrhea: a case report of a novel variant in the glucose-galactose transporter SLC5A1

Introduction

Congenital glucose-galactose malabsorption (CGGM) is a rare autosomal recessive disorder that primarily causes chronic intractable diarrhea. This study aims to describe the clinical history, laboratory profile, diagnostic workflow, and management of the first patient reported with CGGM in Mexico.

Methods

The case involves a Mexican female infant with recurrent admissions to the emergency room since birth due to chronic diarrhea.

Results

The infant was born at term by C-section with a birth weight of 3.120 kg and height of 48 cm for consanguineous parents. She had been breastfed until day 5 of her life when she presented lethargy, diarrhea, abdominal discomfort, and jaundice. During the first evaluation at the emergency room, the significant laboratory finding was blood tyrosine elevation; afterward, amino acid and succinylacetone determinations were obtained, discarding tyrosinemia. When admitted to the hospital, an abdominal ultrasound detected a duplex collecting system. At this time, rice formula was introduced to the patient. She was discharged with jaundice improvement, but diarrhea persisted. Several formula changes had been made from rice to extensively hydrolyzed casein protein to whey-based, with no clinical improvement; the patient still had 10-12 excretions daily. In the second hospitalization, the patient presented anemia, severe dehydration, hyperammonemia, and renal tubular acidosis. A next-generation sequencing panel for inborn errors of metabolism and congenital diarrhea was performed, identifying a homozygous variant in SLC5A1 (c.1667T > C). The diagnosis of CGGM was made at 3 months of age. The infant was initially treated with a modular galactose-glucose-free formula with oil, fructose, casein, minerals, and vitamins until a commercial fructose-based formula was introduced. This led to a complete resolution of diarrhea and improved nutritional status.

Discussion

Diagnosing CGGM is challenging for clinicians, and next-generation sequencing is a valuable tool for providing appropriate treatment. More detailed information on patients with this condition might lead to possible phenotype-genotype correlations. This case's primary clinical and biochemical findings were chronic diarrhea, anemia, jaundice, renal tubular acidosis, hyperammonemia, and initial hypertyrosinemia. Symptoms were resolved entirely with the fructose-based formula.

Congenital Glucose-Galactose Malabsorption: A Case With a Novel SLC5A1 Mutation in a Saudi Infant

While only a few hundred cases have been reported in pediatrics, congenital glucose-galactose malabsorption (GGM) is an extremely rare autosomal-recessive metabolic disorder that is characterized by intractable diarrhea and severe dehydration, which can be life-threatening if not treated appropriately. Due to the rarity of the disease, it is challenging to consider GGM as an initial diagnosis for most clinicians. We report the clinical and diagnostic course of a seven-month-old Saudi infant who presented with severe recurrent episodes of watery diarrhea and failure to thrive in early infancy despite standard treatment. Molecular testing identified that our patient had a compound heterozygous variant in SLC5A1. Fructose-based formulae have been proven to be effective in treating GGM. This case highlights the importance of early diagnosis and timely management to prevent serious complications of undiagnosed GGM.

Efficacy of a Multi-Strain Probiotic Formulation in Pediatric Populations: A Comprehensive Review of Clinical Studies

A probiotic formulation combining Lactobacillus helveticus Rosell^®-52, Bifidobacterium infantis Rosell^®-33, and Bifidobacterium bifidum Rosell^®-71 with fructooligosaccharides, first commercialized in China, has been sold in over 28 countries since 2002. Clinical studies with this blend of strains were conducted mainly in pediatric populations, and most were published in non-English journals. This comprehensive review summarizes the clinical studies in infants and children to evaluate the efficacy of this probiotic for pediatric indications. Literature searches for pediatric studies on Biostime^® or Probiokid^® (non-commercial name) in 6 international and Chinese databases identified 28 studies, which were classified by indications. Twelve studies show that the probiotic significantly increases the efficacy of standard diarrhea treatment regardless of etiology, reducing the risk of unresolved diarrhea (RR 0.31 [0.23; 0.42]; p < 0.0001) by 69%. In eight studies, the probiotic enhanced immune defenses, assessed by levels of various immune competence and mucosal immunity markers (six studies), and reduced the incidence of common infections (two studies). The probiotic improved iron deficiency anemia treatment efficacy (three studies), reducing the risk of unresolved anemia by 49% (RR 0.51 [0.28; 0.92]; p = 0.0263) and significantly reducing treatment side effects by 47% (RR 0.53 [0.37; 0.77]; p = 0.0009). Other studies support further investigation into this probiotic for oral candidiasis, eczema, feeding intolerance in premature babies, or hyperbilirubinemia in newborns.

Chronic diarrhea and skin hyperpigmentation: a new association

BACKGROUND/AIMS

The objective of this study was to describe patients with chronic diarrhea and abnormal skin hyperpigmentation with distinct distribution.

METHODS

This is a retrospective review of children who presented with diarrhea and skin hyperpigmentation. The clinical presentation, laboratory investigations as well as endoscopic and histological data were reviewed.

RESULTS

Seven patients with chronic diarrhea had abnormal skin hyperpigmentation with distinct distribution and presented in the first two months of life. Six patients had other features such as abnormal hair and facial dysmorphism. Mental retardation was reported in one patient. Consanguinity was positive in six patients, and there was family history of consanguinity in four patients, with two patients being siblings. No significant immunodeficiency was reported. Intestinal biopsies were obtained in six patients and showed active chronic inflammation in three patients, partial villous atrophy in two patients, and eosinophilic infiltrate with mild villous atrophy in one patient. Colonic biopsies showed mild focal colitis in three patients and mild colitis with eosinophilic infiltrate in one patient. Skin biopsies showed a greater number of melanophagies with fibrosis of papillary derma in two patients but skin biopsy was normal in one patient. The hair of two patients was analyzed by electron microscopy, which showed an abnormal pattern with decreased pigmentation and diameter; however, its chemical analysis was normal. Two other patients had trichorrhexis nodosa, but no abnormalities were seen in one patient. Chromosomal number was normal in three patients. One patient died because of sepsis, and only one patient was dependent on total parenteral nutrition.

CONCLUSIONS

We believe that this association might represent a new syndrome with an autosomal recessive inheritance that warrants further studies.

New insights into the epidemiology of enteropathogenic Escherichia coli infection

Enteropathogenic Escherichia coli (EPEC) are among the most important pathogens infecting children worldwide and are one of the main causes of persistent diarrhea. EPEC were originally serogroup-defined E. coli associated with infantile diarrhea. As various mechanisms of pathogenesis have been discovered, EPEC classification has come to be based on the presence of specific genes. The eae (intimin) and bfpA (bundle-forming pilus) genes have both been used for identification of EPEC and for subdivision of this group of bacteria into typical and atypical strains. For many years typical EPEC have been considered to be the leading cause of infantile diarrhea in developing countries and were considered rare in industrialized countries. However, current data suggests that atypical EPEC are more prevalent than typical EPEC in both developing and developed countries. Moreover, the duration of diarrhea in patients infected with atypical EPEC is significantly longer than that caused by other pathogens. When comparing the isolation rates of EPEC among children with diarrhea and healthy controls without diarrhea, in general, there is a higher isolation rate in diarrhea, although not significantly higher in all studies. These inconsistencies probably are related to the study patient populations, reflecting a possible age-related susceptibility to infection.