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Rab proteins coordinate inter-organellar vesicle-mediated transport, facilitating intracellular communication, protein recycling, and signaling processes. Dysfunction of Rab proteins or their direct interactors leads to a wide range of diseases with diverse manifestations. We describe seven individuals from four consanguineous Arab Muslim families with an infantile-lethal syndrome, including failure to thrive (FTT), chronic diarrhea, neonatal respiratory distress, variable pituitary dysfunction, and distal arthrogryposis. Exome sequencing analysis in the independent families, followed by an internal gene-matching process using a local exome database, identified a homozygous splice-site variant in MADD(c.2816 + 1 G > A) on a common haplotype. The variant segregated with the disease in all available family members. Determination of cDNA sequence verified single exon skipping, resulting in an out-of-frame deletion. MADDencodes a Rab guanine nucleotide exchange factor (GEF), which activates RAB3 and RAB27A/27B and is thus a crucial regulator of neuromuscular junctions and endocrine secretory granule release. Moreover, MADD protects cells from caspase-mediated TNF-α-induced apoptosis. The combined roles of MADD and its downstream effectors correlate with the phenotypic spectrum of disease, and call for additional studies to confirm the pathogenic mechanism and to investigate possible therapeutic avenues through modulation of TNF-α signaling.

Acute graft-versus-host disease (GVHD) is a major cause of morbidity and mortality in the first 100 days following allogeneic hematopoietic progenitor stem cell transplant. The best diagnostic endoscopic strategy for gastrointestinal (GI) GVHD is a matter of debate. Our aim in the present study was to compare the relative contribution of the endoscopic appearance and biopsies from upper endoscopy and flexible sigmoidoscopy in children with suspected acute GVHD.

Acute graft-versus-host disease (GVHD) is a major cause of morbidity and mortality in the first 100 days following allogeneic hematopoietic progenitor stem cell transplant. The best diagnostic endoscopic strategy for gastrointestinal (GI) GVHD is a matter of debate. Our aim in the present study was to compare the relative contribution of the endoscopic appearance and biopsies from upper endoscopy and flexible sigmoidoscopy in children with suspected acute GVHD. The present study was designed as single-center retrospective chart review cohort study. We reviewed the charts of all of the patients younger than 18 years with suspected acute GI GVHD who had endoscopic evaluation within the first 100 days after stem cell transplant between 1999 and 2009. A total of 48 patients were included. The most common symptoms prompting endoscopic evaluation were diarrhea (70%) and a combination of nausea and vomiting (67%). GVHD was diagnosed in at least 1 biopsy site in 40 of 48 patients (83%). Twenty-two of 40 (55%) patients with GVHD had simultaneous upper and lower endoscopic biopsies, 11 patients had only upper endoscopy, and 7 had only lower endoscopy. The most common endoscopic finding was normal mucosa. The sensitivity for diagnosing GVHD was 77% for both rectosigmoid and upper endoscopic biopsies. Thirty-three of 40 patients had upper endoscopy with biopsies; 28 (85%) had GVHD. The sensitivities and negative predictive value of gastric biopsies were 85% and 63%, whereas for duodenal biopsies they were 50% and 57%, respectively. Rectosigmoid and combined upper endoscopic biopsies are equally sensitive for the diagnosis of acute GI GVHD in children. Flexible sigmoidoscopy can be done unsedated in appropriate patients at the bedside without anesthesia; it can be performed first to identify GI GVHD.

The causes of chronic (CP) and recurrent acute pancreatitis (RAP) in children include anatomic abnormalities and hereditary, metabolic, and autoimmune disorders, with a significant proportion of cases being labeled as idiopathic. Genetic pancreatitis (GP) is associated with mutations of cystic fibrosis transmembrane conductor regulator gene (CFTR), cationic trypsinogen (PRSS1) gene, and serine protease inhibitor Kazal type 1 (SPINK1). There literature is sparse regarding the clinical profile of GP in children. The aim of the present study was to estimate the prevalence and describe the clinical characteristics and outcome of genetic pancreatitis.

The causes of chronic (CP) and recurrent acute pancreatitis (RAP) in children include anatomic abnormalities and hereditary, metabolic, and autoimmune disorders, with a significant proportion of cases being labeled as idiopathic. Genetic pancreatitis (GP) is associated with mutations of cystic fibrosis transmembrane conductor regulator gene (CFTR), cationic trypsinogen (PRSS1) gene, and serine protease inhibitor Kazal type 1 (SPINK1). There literature is sparse regarding the clinical profile of GP in children. The aim of the present study was to estimate the prevalence and describe the clinical characteristics and outcome of genetic pancreatitis. We reviewed the charts of children ages 18 years or younger with RAP or CP diagnosed from 2000 to 2009 at the Children's Hospital of Wisconsin, Milwaukee. Twenty-nine patients with RAP or CP were identified, of whom 23 (79%) were positive for mutations in =1 of the above-mentioned genes, and were included for review. The median age of symptom onset was 5 years (range 9 months–15 years) with diagnosis at 6.5 years (range 1–16 years). Twenty-one were white; 14 were girls. The most common presenting symptoms were abdominal pain and vomiting. Patients with RAP had 2 to 8 episodes of pancreatitis during 3.6-year average follow-up. Family history was positive in 5 of 29 of gene-tested patients. CFTR, SPINK1, or PRSS1mutations were seen in 14 (48%), 8 (27%), and 7 (24%) patients, respectively. Two patients were homozygous for CFTRmutations, 6 heterozygote and 4 patients had 5 T variants. Two other patients had double heterozygous mutations in F508 del/2789 + 5G > A and F508 del/5T variant. Six patients with CP had a combination of CFTRand SPINK1or PRSS1mutations. Eleven of 29 (38%) patients met radiological criteria for CP. All of the heterozygote patients with a combination of CFTRand SPINK1or PRSS1mutations had CP. Eight patients developed a chronic pain syndrome and 2 developed exocrine pancreatic insufficiency during follow-up. We found a high prevalence of genetic mutations in patients without anatomic or metabolic abnormalities known to be associated with pancreatitis. Studies are needed to ascertain the genetic causes of RAP and CP and examine the relation between single CFTRmutations and single mutations in the PRSS1and SPINK1genes.

We report on a female infant with congenital iron storage disease, facial dysmorphism, intractable diarrhea, and hair abnormalities. The intractable diarrhea failed to resolve despite total parenteral nutrition and complete bowel rest for more than 3 weeks. The patient also had elevated liver enzymes and failure to thrive. Histopathologic examination of the liver revealed marked iron deposits in hepatocytes with portal edema, fibrosis, and septal formation. No metabolic abnormalities could be detected. She died at the age of 10 months. We suggest that this case could have a specific iron storage syndrome that is similar to the two sibs reported by Stankler et al. [1982; Arch Dis Child 57:212–216] and Verloes et al. [1997; Am J Med Genet 68:391–395]. The condition was called the tricho‐hepato‐enteric (THE) syndrome. © 2007 Wiley‐Liss, Inc.