Tricho-hepato-enteric syndrome
Overview
Tricho-hepato-enteric syndrome (THE), also known as syndromic or phenotypic diarrhea, is an extremely rare congenital bowel disorder which manifests itself as intractable diarrhea in infants with intrauterine growth retardation, hair and facial abnormalities
Symptoms
Tricho-hepato-enteric syndrome is one particular form of intractable diarrhea of infancy, presenting typically in the first month of life. These babies were usually born small for their age and continue to experience failure to thrive, usually with a final short stature. Typical facial features include prominent forehead and cheeks, a broad nasal root and widely spaces eyes (hypertelorism). Their hairs are woolly, easily removed and poorly pigmented. Liver disease is mainly present as cirrhosis or fibrosis, and staining might reveal high iron content of the liver cells (consistent with hemochromatosis). Most evaluated patients had some degree of decrease in intelligence.
Causes
It is thought to be a genetic disorder with an autosomal recessive inheritance pattern, although responsible genes have not been found and the exact cause remains unknown.
Diagnosis
Microscopic examination of a biopsy of the small bowel in these patients shows villous atrophy with low or no mononuclear cell infiltration of the lamina propria nor specific abnormalities involving the epithelium. The amount of villous atrophy does not explain the severity of the diarrhea. Microscopic analysis of the hair shows twisted hairs of unequal size and different shapes (pili torti, aniso- and poikilotrichosis), longitudinal breaks and breaks located at nodes (trichorrhexis nodosa). Scanning electron microscopy might reveal hair budding (trichorrhexis blastysis). Biochemical analysis might reveal sulfur-deficient brittle hair (trichothiodystrophy; note that disulfide bonds determine hair waviness). Immune deficiency has been reported under the form of T cell dysfunction and abnormal antibody generation.
Prognosis
Prognosis is poor; many patients die before the age of 5 (mainly from infections or cirrhosis), although most patients nowadays survive with intravenous feeding (parenteral nutrition).
Treatment
No specific treatment or cure exists. Affected children usually need total parenteral nutrition through a central venous catheter. Further worsening of liver damage should however be avoided if possible. Diarrhea will likely continue even though food stops passing through the gastrointestinal system. They can subsequently be managed with tube feeding, and some may be weaned from nutritional support during adolescence.