Immunodeficiency and inborn disorders of vitamin B12 and folate metabolism.

PURPOSE OF REVIEW: Immune dysfunction, including severe combined immunodeficiency, has been described in genetic disorders affecting the metabolism of the vitamins cobalamin (vitamin B12) and folate. We have reviewed reports of clinical findings in patients with a number of inborn errors of cobalamin or folate metabolism, specifically looking for immune problems. RECENT FINDINGS: There is little evidence that immune function is affected in most of the disorders. Exceptions are Imerslund-Gräsbeck syndrome and hereditary folate malabsorption (affecting intestinal absorption of cobalamin and folate, respectively), transcobalamin deficiency (affecting transport of cobalamin in blood and cellular cobalamin uptake), and methylenetetrahydrofolate dehydrogenase 1 deficiency (catalyzing cytoplasmic interconversion of reduced folate coenzyme derivatives). SUMMARY: Although some inborn errors of cobalamin or folate can be associated with immune dysfunction, the degree and type of immune dysfunction vary with no obvious pattern.

Intestinal Failure: A Description of the Problem and Recent Therapeutic Advances.

Pediatric intestinal failure occurs when gut function is insufficient to meet the nutrient and hydration needs of the growing child. The commonest cause is short bowel syndrome with maldigestion and malabsorption following massive bowel loss. The remnant bowel adapts during the process of intestinal rehabilitation. Management promotes the achievement of enteral autonomy while mitigating the risk of comorbid disease. The future of care is likely to see expansion of pharmacologic methods for augmenting bowel adaptation, tissue engineering techniques enabling immune suppression-free autologous bowel transplant, and the development of electronic health record tools for efficient, collaborative study and care improvement.

[IMERSLUND-GRÄSBECK SYNDROME CONGENITAL FORM OF VITAMIN B12 DEFICIENCY ANEMIA].

Normal red blood cells maturation depends on many different hematological factors, including vitamin (vit.) B12. Megaloblastic anemias are basically caused by vit. B12 deficiency. In childhood the deficiency of this vitamin is extremely rare. The article captures findings of observation of the patient with rare form congenital vit. B12 deficiency anemia - Imerslund-Gräsbeck syndrome. The disease is characterized with selective intestinal malabsorption of vit. B12 and permanent proteinuria, without sings of kidney disease. The diagnosis was confirmed by our team in early childhood and based on the history, clinical and paraclinical data. After two weeks of specific treatment with vit. B12 , complete clinical - hematological remission was achieved. Treatment includes lifelong vit. B12 injections once per month. Cathamnesic observation for 18 months revealed that the patient is in remission, but there was continued macrocytosis of red blood cells and mild proteinuria. The presented case is interesting as a rare case of megaloblastic anemia caused by vit. B12 deficiency in childhood. Such patients often treated under different diagnosis. In such cases early diagnosis, treatment and prevention are crucial for the good prognosis.

A Rare Cause of Intractable Diarrhea of Infancy.

Intractable watery diarrhea presenting in the neonatal period is a relatively uncommon condition. Congenital disorders of malabsorption are among the major causes of prolonged watery diarrhea. This is the case report of a 3-month male infant born to consanguineous parents, who presented with intractable diarrhea since birth. He was failing to thrive and wasted. Persistent diarrhea lead to prolonged hospitalisation and recurrent hypernatremic dehydration. Relevant investigations clinched the diagnosis of ''congenital glucose galactose malabsorption (CGGM)''. The astute clinician should have a high index of suspicion regarding such rare causes of diarrhea in early infancy, as an appropriate rational diagnosis can lead to life-saving treatment as depicted in this case report.

Congenital Fatal Diarrhea in Newborns.

Microvillus inclusion disease is a rare autosomal recessive disorder of intestinal epithelium causing intractable secretary diarrhea in the first two months of life and about 140 cases have been reported worldwide till now. Here authors report 2 cases of Microvillus inclusion disease (MVID) diagnosed in neonates by electron microscopy study of small intestinal biopsy.

A New Case of Congenital Malabsorptive Diarrhea and Diabetes Secondary to Mutant Neurogenin-3.

Congenital diarrheal disorders are a group of rare enteropathies that often present with life-threatening diarrhea in the first weeks of life. Enteric anendocrinosis, characterized by a lack of intestinal enteroendocrine cells due to recessively inherited mutations in the Neurogenin-3 (NEUROG3) gene, has been described as a cause of congenital malabsorptive diarrhea. Diabetes mellitus also is typically associated with NEUROG3 mutations, be it early onset or a later presentation. Here we report a case of a 16-year-old male patient with severe malabsorptive diarrhea from birth, who was parenteral nutrition dependent and who developed diabetes mellitus at 11 years old. To the best of our knowledge, only 9 cases of recessively inherited NEUROG3 mutations have been reported in the literature to date. Our patient presents with several remarkable differences compared with previously published cases. This report can contribute by deepening our knowledge on new aspects of such an extremely rare disease.

Congenital Glucose-Galactose Malabsorption: A Case Report.

Congenital glucose-galactose malabsorption (CGGM) is a rare cause of intractable infantile diarrhea, with only a few hundred cases recognized worldwide. This life-threatening disorder must be considered in the differential diagnosis of an infant who presents with diarrhea and dehydration that fails to respond to standard therapy. The clinical and diagnostic course of an infant with recurrent episodes of watery diarrhea and hypernatremic dehydration found to be homozygous for a rare variant in the SLC5A1 gene, c.187C>T (p.R63X) is described.

Congenital glucose-galactose malabsorption: a descriptive study of clinical characteristics and outcome from Western Saudi Arabia.

BACKGROUND AND STUDY AIMS: Congenital glucose galactose malabsorption (CGGM) is a rare autosomal recessive disorder caused by a defect in the sodium-coupled transport of glucose and galactose across the intestinal brush border presenting with neonatal diarrhoea. The aim of this study was to report the clinical and laboratory characteristics of patients with CGGM from the Western Saudi Arabia. PATIENTS AND METHODS: This is a retrospective review of CGGM patients in three major hospitals in the city of Jeddah, Saudi Arabia, namely King Abdulaziz University Hospital, King Faisal Specialist Hospital and Research Centre, and Maternity Children Hospital in the period between November 2001 and October 2011. RESULTS: Twenty-four patients with CGGM have been described. The median age at diagnosis was 4.5 months. Twelve (50%) were males. Sixteen (66.7%) were Saudi and 8 (33.3%) were non Saudi (5 Arabs and 3 Asians). Parents of 21 patients were consanguineous. Nine (37.5%) had affected siblings with CGGM. All presented with diarrhoea resulted in dehydration. Hypernatremia was seen in 7 (29.2%) patients, renal tubular acidosis in 4 patients. Renal stones and nephrocalcinosis were detected in 3 (12.5%) patients at 8 months, 12 months and 7 years, respectively. The median follow up was 41.6 months. All but three demonstrated normal weight gain. Five patients reported one or more symptoms of bloating (n=3), diarrhoea (n=3) and abdominal pain (n=1) during follow up. All had normal development and none had neurological complications secondary to dehydration. CONCLUSION: Early recognition and management of this condition are crucial to prevent consequences of dehydration and death.

Exome sequencing finds a novel PCSK1 mutation in a child with generalized malabsorptive diarrhea and diabetes insipidus.

OBJECTIVES: Congenital diarrhea disorders are a group of genetically diverse and typically autosomal recessive disorders that have yet to be well characterized phenotypically or molecularly. Diagnostic assessments are generally limited to nutritional challenges and histologic evaluation, and many subjects eventually require a prolonged course of intravenous nutrition. Here we describe next-generation sequencing techniques to investigate a child with perplexing congenital malabsorptive diarrhea and other presumably unrelated clinical problems; this method provides an alternative approach to molecular diagnosis. METHODS: We screened the diploid genome of an affected individual, using exome sequencing, for uncommon variants that have observed protein-coding consequences. We assessed the functional activity of the mutant protein, as well as its lack of expression using immunohistochemistry. RESULTS: Among several rare variants detected was a homozygous nonsense mutation in the catalytic domain of the proprotein convertase subtilisin/kexin type 1 gene. The mutation abolishes prohormone convertase 1/3 endoprotease activity as well as expression in the intestine. These primary genetic findings prompted a careful endocrine reevaluation of the child at 4.5 years of age, and multiple significant problems were subsequently identified consistent with the known phenotypic consequences of proprotein convertase subtilisin/kexin type 1 (PCSK1) gene mutations. Based on the molecular diagnosis, alternate medical and dietary management was implemented for diabetes insipidus, polyphagia, and micropenis. CONCLUSIONS: Whole-exome sequencing provides a powerful diagnostic tool to clinicians managing rare genetic disorders with multiple perplexing clinical manifestations.

Brown bowel syndrome (intestinal lipofuscinosis) - a case report and review of the literature.

Brown bowel syndrome (BBS) is a very rare condition occurring in association with malabsorption syndromes. It is characterised by deposition of granular, brown pigment (lipofuscin or ceroid) in intestinal smooth muscles. Rarely BBS can be complicated by distention of any segment of the bowel. We present a case of BBS associated with massive dilation of first loop of the small intestine and moderate dilation of the sigmoid colon with functional intestinal disturbances requiring surgical intervention in an 11-year-old boy.

[Neonatal diarrhea due to congenital glucose-galactose malabsorption: report of seven cases]. / Diarrhée néonatale par malabsorption du glucose et du galactose : à propos de 7 observations.

Congenital glucose-galactose malabsorption (CGGM) is a rare autosomal recessive disorder, which presents as a protracted diarrhea in early neonatal life. We describe the clinical history, diagnostic evaluation, and management of 7 children with CGGM in western France. There were 4 girls and 3 boys from 5 families, born between 1984 and 2010. The principal complaint was a neonatal onset of watery and acidic severe diarrhea complicated by hypertonic dehydration. The diarrhea stopped with fasting. In 2 cases, the family history supported the diagnosis. In the other cases, elimination of glucose and galactose (lactose) from the diet resulted in the complete resolution of diarrhea symptoms. In 2 cases, the H2 breath tests were positive. In 2 cases, the HGPO or oral glucose tolerance test (OGTT) demonstrated an abnormal curve with glucose and a normal curve with fructose. DNA sequencing was not used. When glucose and galactose were eliminated from the diet, the infants had normal growth and development. In conclusion, CGGM is a rare etiology of neonatal diarrhea; however, the diagnosis is easy to make and the prognosis is excellent.

Congenital diarrheal disorders: an updated diagnostic approach.

Congenital diarrheal disorders (CDDs) are a group of inherited enteropathies with a typical onset early in the life. Infants with these disorders have frequently chronic diarrhea of sufficient severity to require parenteral nutrition. For most CDDs the disease-gene is known and molecular analysis may contribute to an unequivocal diagnosis. We review CDDs on the basis of the genetic defect, focusing on the significant contribution of molecular analysis in the complex, multistep diagnostic work-up.

A case of neonatal diarrhoea caused by congenital glucose-galactose malabsorption.

A five-month-old Indian girl, product of consanguineous marriage, presented with diarrhoea with an onset within two days after birth, severe malnutrition and metabolic acidosis. The diarrhoea persisted even with lactose-free formula, amino acid-based formula and glucose-containing oral rehydration solution, but stopped when fasted. She required prolonged parenteral nutrition. Fructose and glucose tolerance tests were performed, confirming the child was able to absorb and metabolize fructose but not glucose, indicating a diagnosis of glucose-galactose malabsorption. This case illustrate how simple and pertinent clinical observations and laboratory investigations is sufficient to allow a firm diagnosis to be made.

D28G mutation in congenital glucose-galactose malabsorption.

BACKGROUND: Congenital glucose-galactose malabsorption is a rare autosomal recessive disorder of the intestinal transport of glucose and galactose, leading to watery diarrhea, dehydration, failure to thrive, and early death. METHODS: In this study, we analyzed D28G mutation in 16 family members of a patient with typical presentation of congenital glucose-galactose malabsorption with polymerase chain reaction-Restriction Fragment Length Polymorphism method. RESULTS: Nine members of this family were heterozygous for D28G mutation. CONCLUSION: To the best of our knowledge this is the first report of D28G mutation in Iran. Moreover, this simple typical PCR-Restriction Fragment Length Polymorphism method, allows immediate identification of D28G mutation.

Novel mutations in the human sucrase-isomaltase gene (SI) that cause congenital carbohydrate malabsorption.

Disaccharide intolerance I or congenital sucrase-isomaltase deficiency (CSID) is a disorder leading to maldigestion of disaccharides, which is autosomal recessively inherited. Here we analyzed the sucrase-isomaltase (SI) gene from 11 patients of Hungarian origin with congenital sucrase-isomaltase deficiency. Variants in the SI gene had previously been described in CSID patients, which cause amino acid exchanges that affect the transport, the processing, or the function of the SI protein. None of our patients had known mutations for CSID. Our analyses revealed 43 SI variants in total, 15 within exons and one at a splice site. Eight of the exonic mutations lead to amino acid exchanges, causing hypomorph or null alleles. One new variation affects a splice site, which is also predicted to result in a null allele. All potential pathological alterations were present on one allele only. In six out of the 11 patients the phenotype of CSID could be explained by compound heterozygosity.

[Microvillus inclusion disease, a rare cause of severe congenital diarrhea]. / Microvillusinclusieziekte, een zeldzame oorzaak van ernstige aangeboren diarree.

To date, microvillus inclusion disease (MID) has been diagnosed in six Dutch patients. It is a rare autosomal recessive hereditary intestinal disorder mostly presenting with malabsorption and severe secretory diarrhoea from birth. The diagnosis is confirmed by electron microscopy of intestinal mucosal biopsies, which show characteristic intracytoplasmic vesicles containing clearly recognisable microvilli and irregularly distributed microvilli in the brush border. The two clinical forms of the disease that have been recognised internationally, a 'congenital' and a 'late-onset' form of MID, have also been observed in the Dutch patients. At the last follow-up five patients had died, the sixth was 17 years old and alive. The pathogenesis and genetics of MID are, as yet, unknown. Eventually, all patients die from complications of the disease, notably from the total parenteral nutrition. The only chance of survival is intestinal or combined liver-intestinal transplantation.