Tricho-hepato-enteric syndrome: a case of hemochromatosis with intractable diarrhea, dysmorphic features, and hair abnormality

Trichohepatoenteric Syndrome: A Report of Two Children From Bahrain With a Novel Mutation and a Literature Review

Trichohepatoenteric syndrome (THES) is a rare genetic disorder inherited in an autosomal recessive manner. THES primarily leads to neonatal enteropathy, typically manifesting as severe, persistent diarrhea, distinctive facial features such as frontal bossing and a broad flat nasal bridge, woolly and fragile hair, immunodeficiency resulting in recurrent infections, failure to thrive (FTT), and liver complications including fibrosis or cirrhosis. This multisystem disorder is linked to mutations in the tetratricopeptide repeat domain 37 (TTC37) gene, also known as superkiller complex (SKIC) protein 3, responsible for THES type 1, and the Ski2-like ribonucleic acid (RNA) helicase (SKIV2L) gene, also known as SKIC2, responsible for THES type 2. This case report describes two far-related pediatric patients from Bahrain diagnosed with THES type 1. Although both patients exhibited typical symptoms of this syndrome, the first patient had more severe symptoms. Diagnostic genetic evaluations confirmed THES. Patient 1 had three homozygous variants in the TTC37 gene, while Patient 2 had two variants in the same gene. Both of our patients had a novel homozygous variant. The treatment focused on supportive care and infection management. Despite these efforts, patients did not reach their growth potential. This report underscores the necessity for early identification of THES to facilitate appropriate management and genetic counseling.

Diet management in congenital diarrheas and enteropathies - general concepts and disease-specific approach, a narrative review

Congenital diarrheas and enteropathies (CODE) are a group of rare, heterogenous, monogenic disorders that lead to chronic diarrhea in infancy. Definitive treatment is rarely available, and supportive treatment is the mainstay. Nutritional management in the form of either specialized formulas, restrictive diet, or parenteral nutrition support in CODE with poor enteral tolerance is the cornerstone of CODE treatment and long-term growth. The evidence to support the use of specific diet regimens and nutritional approaches in most CODE disorders is limited due to the rarity of these diseases and the scant published clinical experience. The goal of this review was to create a comprehensive guide for nutritional management in CODE, based on the currently available literature, disease mechanism, and the PediCODE group experience. Enteral diet management in CODE can be divided into 3 distinct conceptual frameworks: nutrient elimination, nutrient supplementation, and generalized nutrient restriction. Response to nutrient elimination or supplementation can lead to resolution or significant improvement in the chronic diarrhea of CODE and resumption of normal growth. This pattern can be seen in CODE due to carbohydrate malabsorption, defects in fat absorption, and occasionally in electrolyte transport defects. In contrast, general diet restriction is mainly supportive. However, occasionally it allows parenteral nutrition weaning or reduction over time, mainly in enteroendocrine defects and rarely in epithelial trafficking and polarity defects. Further research is required to better elucidate the role of diet in the treatment of CODE and the appropriate diet management for each disease.

Tricho-hepato-enteric syndrome: Retrospective multicenter experience in Saudi Arabia

BACKGROUND

Trichohepatoenteric syndrome (THES) is a very rare disorder that is characterized by intractable congenital diarrhea, woolly hair, intrauterine growth restriction, facial dysmorphism, and short stature. Our knowledge of THES is limited due to the small number of reported cases.

METHODS

Thirty patients diagnosed with THES, all molecularly confirmed by whole exome sequencing (WES) to have biallelic variants in TTC37 or SKIV2L, were included in the study. Clinical, biochemical, and nutritional phenotypes and outcome data were collected from all participants.

RESULTS

The median age of THES patients was 3.7 years (0.9-23 years). Diarrhea and malnutrition were the most common clinical features (100%). Other common features included hair abnormalities (96%), skin hyperpigmentation (87%), facial dysmorphic abnormalities (73%), psychomotor retardation (57%), and hepatic abnormalities (30%). Twenty-five patients required parenteral nutrition (83%) with a mean duration of 13.34 months, and nearly half were eventually weaned off. Parenteral nutrition was associated with a poor prognosis. The vast majority of cases (89.6%) had biallelic variants in SKIV2L, with biallelic variants in TTC37 accounting for the remaining cases. A total of seven variants were identified in TTC37 (n = 3) and SKIV2L (n = 4). The underlying genotype influenced some phenotypic aspects, especially liver involvement, which was more common in TTC37-related THES.

CONCLUSION

Our data helps define the natural history of THES and provide clinical management guidelines.

An RNA Metabolism and Surveillance Quartet in the Major Histocompatibility Complex

At the central region of the mammalian major histocompatibility complex (MHC) is a complement gene cluster that codes for constituents of complement C3 convertases (C2, factor B and C4). Complement activation drives the humoral effector functions for immune response. Sandwiched between the genes for serine proteinase factor B and anchor protein C4 are four less known but critically important genes coding for essential functions related to metabolism and surveillance of RNA during the transcriptional and translational processes of gene expression. These four genes are NELF-E (RD), SKIV2L (SKI2W), DXO (DOM3Z) and STK19 (RP1 or G11) and dubbed as NSDK. NELF-E is the subunit E of negative elongation factor responsible for promoter proximal pause of transcription. SKIV2L is the RNA helicase for cytoplasmic exosomes responsible for degradation of de-polyadenylated mRNA and viral RNA. DXO is a powerful enzyme with pyro-phosphohydrolase activity towards 5' triphosphorylated RNA, decapping and exoribonuclease activities of faulty nuclear RNA molecules. STK19 is a nuclear kinase that phosphorylates RNA-binding proteins during transcription. STK19 is also involved in DNA repair during active transcription and in nuclear signal transduction. The genetic, biochemical and functional properties for NSDK in the MHC largely stay as a secret for many immunologists. Here we briefly review the roles of (a) NELF-E on transcriptional pausing; (b) SKIV2L on turnover of deadenylated or expired RNA 3'→5' through the Ski-exosome complex, and modulation of inflammatory response initiated by retinoic acid-inducible gene 1-like receptor (RLR) sensing of viral infections; (c) DXO on quality control of RNA integrity through recognition of 5' caps and destruction of faulty adducts in 5'→3' fashion; and (d) STK19 on nuclear protein phosphorylations. There is compelling evidence that a dysregulation or a deficiency of a NSDK gene would cause a malignant, immunologic or digestive disease.

Tricho-hepato-enteric syndrome with novel SKIV2L gene mutations: A case report

RATIONALE

Tricho-hepato-enteric syndrome (THES) is a rare disorder caused by mutations in the TTC37 or SKIV2L genes and characterized by chronic diarrhea, liver disease, hair abnormalities, and high mortality in early childhood due to severe infection or liver cirrhosis.

PATIENT CONCERNS

The patient is the second child of three siblings born to non-consanguineous healthy Japanese parents. She had intrauterine growth retardation and was delivered at 33 weeks of gestation due to placental abruption. She presented with watery diarrhea, elevated levels of liver enzymes, multiple episodes of recurrent bacterial infection, and mild mental retardation. She had facial dysmorphism, including prominent forehead and hypertelorism, and had woolly hair without trichorrhexis nodosa.

DIAGNOSIS

Clinical features led to consideration of THES. Novel compound heterozygous nonsense mutations, c.1420G>T (p.Q474*) and c.3262G>T (p.E1088*), in the SKIV2L gene were identified in the patient, and decreased levels of SKIV2L protein expression were revealed by flow cytometry and confirmed by western blot analysis using patient peripheral blood mononuclear cells (PBMCs).

INTERVENTIONS

Total parenteral nutrition was required from day 30 to day 100. Trimethoprim-sulfamethoxazole prophylaxis was started at the age of 7 years after multiple episodes of bacterial pneumonia and otitis media.

OUTCOMES

Chronic diarrhea persisted for more than 10 years, but the symptoms gradually improved with age. At the age of 13 years, she started a normal diet in combination with oral nutritional supplementation and her height and weight were just below the 3rd percentile for healthy individuals. She developed secondary sex characteristics, and menarche occurred at the age of 12 years. Facial dysmorphism, including prominent forehead and hypertelorism, and woolly hair without trichorrhexis nodosa became noticeable as she matured.

LESSONS

Physicians must be aware of THES when they encounter a patient with infantile diarrhea, hair abnormalities, immune deficiency, mental retardation, and liver disease. Moreover, flow cytometric detection of SKIV2L protein in PBMCs may facilitate early diagnosis.

Management of syndromic diarrhea/tricho-hepato-enteric syndrome: A review of the literature

Syndromic diarrhea/tricho-hepato-enteric syndrome (SD/THE) is a rare disease linked to the loss of function of either TTC37 or SKIV2L, two components of the SKI complex. It is characterized by a combination of 9 signs (intractable diarrhea, hair abnormalities, facial dysmorphism, immune abnormalities, IUGR/SGA, liver abnormalities, skin abnormalities, congenital heart defect and platelet abnormalities). We present a comprehensive review of the management of SD/THE and tested therapeutic regimens. A review of the literature was conducted in May 2017: 29 articles and 2 abstracts were included describing a total of 80 patients, of which 40 presented with mutations of TTC37, 14 of SKIV2L. Parenteral nutrition was used in the management of 83% of the patients and weaned in 44% (mean duration of 14.97 months). Immunoglobulins were used in 33 patients, but data on efficacy was reported for 6 patients with a diminution of infection (n = 3) or diarrhea reduction (n = 2). Antibiotics (n = 11) provided no efficacy. Steroids (n = 17) and immunosuppressant drugs (n = 13) were used with little efficacy and mostly in patients with IBD-like SD/THE. Hematopoietic stem cell transplantation (HSCT) was performed in 4 patients: 2 died, for one it corrected the immune defects but not the other features and for the last one, it provided only a partial improvement. Finally, no specific diet was effective except for some contradictory reports for elemental formula. In conclusion, the management of SD/THE mainly involves parenteral nutrition and immunoglobulin supplementation. Antibiotics, steroids, immunosuppressants, and HSCT are not recommended as principle treatments since there is no evidence of efficacy.

Trichohepatoenteric Syndrome or Syndromic Diarrhea-Report of Three Members in a Family, First Report from Iran

Introduction. Intractable diarrhea of infancy (IDI) includes several types of early onset diarrhea; one of the rare etiologies is trichohepatoenteric (THE) syndrome, also known as syndromic diarrhea (SD) which was primarily described by Stankler et al. Hereby we report a family with several affected members which to our knowledge is the first case report from Iran. Report of Cases. A three-year-old boy referred with short stature, poor weight gain, and intermittent steatotic diarrhea to our center. He was born to healthy, relative parents (cousins). He did not gain any weight after four months of age and began having intermittent steatotic diarrhea, abdominal distension, and fever. He was hospitalized several times. Two other children in the family also showed somewhat similar symptoms. Two sweat tests were negative for cystic fibrosis. Workup for Celiac disease was performed several times which was negative; however, gluten-free diet was tried several times which was not effective. Workup for Hirschsprung's disease was performed but colon was ganglionic. Evidence of liver involvement was approved by elevated liver enzymes and coarse echo of liver on sonography. Discussion. Trichoenterohepatic syndrome should be put in mind in cases of intractable diarrhea presenting in a family with several affected members. Early diagnosis would save patients from unnecessary workups.

Syndromic (phenotypic) diarrhoea of infancy/tricho-hepato-enteric syndrome

OBJECTIVES

Syndromic diarrhoea/tricho-hepato-enteric syndrome (SD/THE) is a rare congenital syndrome. The main features are intractable diarrhoea of infancy, hair abnormalities, facial dysmorphism, intrauterine growth restriction and immune system abnormalities. It has been linked to abnormalities in two components of the putative human ski complex: SKIV2L and TTC37. The long-term outcome of this syndrome is still unknown. We aim to describe the long-term outcome, in the French cohort of patients born since 1992.

DESIGN

Review of the clinical and biological features of the 15 patients with SD/THE, followed in France and born between 1992 and 2010.

RESULTS

All patients presented typical SD/THE syndrome features, of intractable diarrhoea in infancy requiring parenteral nutrition, a facial dysmorphism with hair abnormalities, and immunological disorders. Half of them also had liver and skin abnormalities. Five children died, among which 3 died due to infections. Probabilities of survival according to the Kaplan-Meier method were 93.3%, 86.7%, 74.3 and 61.9%, respectively at 1 year, 5 years, 10 years and 15 years of age. 3/15 were weaned from parenteral nutrition (PN) with likelihood of weaning being 10% at 5 years and 40% at 10 years. At birth 80% were small for gestational age and the short stature persisted in 60%. Haemophagocytic syndrome was noted in 60% and mild mental retardation was present in 60%.

CONCLUSIONS

SD/THE is a rare disease with high morbidity and mortality. Management should be focused on nutrition and immunological defects.

Syndromic diarrhea/Tricho-hepato-enteric syndrome

Abstract

Syndromic diarrhea/Tricho-hepato-enteric syndrome (SD/THE) is a rare and severe bowel disorder caused by mutation in SKIV2L or in TTC37, 2 genes encoding subunits of the putative human SKI complex. The estimated prevalence is 1/1,000,000 births and the transmission is autosomal recessive. The classical form is characterized by 5 clinical signs: intractable diarrhea of infancy beginning in the first month of life, usually leading to failure to thrive and requiring parenteral nutrition; facial dysmorphism characterised by prominent forehead and cheeks, broad nasal root and hypertelorism; hair abnormalities described as woolly and easily removable; immune disorders resulting from defective antibody production; intrauterine growth restriction. The aetiology is a defect in TTC37, a TPR containing protein, or in the RNA helicase SKIV2L, both constituting the putative human ski complex. The ski complex is a heterotetrameric cofactor of the cytoplasmic RNA exosome which ensures aberrants mRNAs decay. The diagnosis SD/THE is initially based on clinical findings and confirmed by direct sequencing of TTC37 and SKIV2L. Differential diagnosis with the other causes of intractable diarrhea is easily performed by pathologic investigations. During their clinical course, most of the children require parenteral nutrition and often immunoglobulin supplementation. With time, some of them can be weaned off parenteral nutrition and immunoglobulin supplementation. The prognosis depends on the management and is largely related to the occurrence of parenteral nutrition complications or infections. Even with optimal management, most of the children seem to experience failure to thrive and final short stature. Mild mental retardation is observed in half of the cases.

Abstract in French

Les diarrhées syndromiques ou syndrome tricho-hepato-enterique (SD/THE) sont un syndrome rare et sévère dont l’incidence est estimée à 1 cas pour 1 million de naissances et la transmission autosomique récessive. La forme typique associe 5 signes cliniques: une diarrhée grave rebelle nécessitant dans la majorité des cas une nutrition parentérale du fait de la malnutrition, une dysmorphie avec un front large et bombé, une racine du nez large et un hypertélorisme, des anomalies des cheveux qui sont fragiles, cassants, incoiffables et qualifiés de « laineux », un retard de croissance intra utérine et des anomalies de l’immunité à type de déficit en immunoglobuline ou d’absence de réponse aux antigènes vaccinaux. Des anomalies de deux protéines peuvent être à l’origine du syndrome SD/THE: TTC37, une protéine à motif TPR et SKIV2L, une hélicase à ARN, toutes 2 étant des constituants du complexe SKI humain. Le complexe SKI est un co-facteur de l’exosome cytoplasmique qui assure la dégradation des ARN aberrants ou exogènes. Le diagnostic est d’abord clinique puis confirmé par le séquençage des gènes TTC37 et SKIV2L. Le diagnostic différentiel avec les autres formes de diarrhées intraitables est fait grâce aux analyses anatomopathologiques qui montrent dans les autres formes, des lésions spécifiques. La prise en charge clinique repose sur la nutrition parentérale et la supplémentation en immunoglobuline si nécessaire. Un certain nombre d’enfants peuvent être sevrés de la nutrition parentérale et des supplémentations en immunoglobulines. En cas d’atteinte hépatique, celle-ci peut être sévère et conduire au décès. Même avec une prise en charge optimale, les enfants présentent une petite taille et, dans la moitié des cas, un retard mental modéré.

Disease name/synonyms – Syndromic diarrhea – Phenotypic diarrhea – Tricho-hepato-enteric syndrome – Intractable diarrhea of infancy with facial dysmorphism – Trichorrhexis nodosa and cirrhosis – Neonatal hemochromatosis phenotype with intractable diarrhea and hair abnormalities – Intractable infant diarrhea associated with phenotypic abnormalities and immune deficiency- Syndromatic diarrhea. [ORPHA84064 MIM 222470 and MIM614602]. Possibly chronic diarrhea and skin hyperpigmentation.

Trichohepatoenteric syndrome: founder mutation in asian indians

Trichohepatoenteric syndrome (THES) is characterized by chronic diarrhea, dysmorphic facies and hair abnormalities. Hepatic involvement varies from no abnormality to cirrhosis and hemochromatosis. Recently, mutations in the tetratricopeptide repeat domain 37 (TTC37) gene were identified to cause THES. The c.2808G>A variation was suggested as a possible founder mutation among the South Asians. We further report 2 unrelated cases of Asian-Indian ethnicity (Gujrati) with THES, wherein targeted mutation analysis revealed the same mutation in homozygous form in both cases. These findings, as well as haplotype analysis, corroborate the founder mutation hypothesis amongst Asian Indo-Pakistani ethnic groups. A restriction enzyme-based method is also described to identify this founder mutation. One of our probands had multiple hepatic hemangiomas, a feature not previously observed in this syndrome.

Mutations in TTC37 cause trichohepatoenteric syndrome (phenotypic diarrhea of infancy)

BACKGROUND & AIMS

Trichohepatoenteric syndrome (THES) is an autosomal-recessive disorder characterized by life-threatening diarrhea in infancy, immunodeficiency, liver disease, trichorrhexis nodosa, facial dysmorphism, hypopigmentation, and cardiac defects. We attempted to characterize the phenotype and elucidate the molecular basis of THES.

METHODS

Twelve patients with classic THES from 11 families had detailed phenotyping. Autozygosity mapping was undertaken in 8 patients from consanguineous families using 250,000 single nucleotide polymorphism arrays and linked regions evaluated using microsatellite markers. Linkage was confirmed to one region from which candidate genes were analyzed. The effect of mutations on protein production and/or localization in hepatocytes and intestinal epithelial cells from affected patients was characterized by immunohistochemistry.

RESULTS

Previously unrecognized platelet abnormalities (reduced platelet alpha-granules, unusual stimulated alpha granule content release, abnormal lipid inclusions, abnormal platelet canalicular system, and reduced number of microtubules) were identified. The THES locus was mapped to 5q14.3-5q21.2. Sequencing of candidate genes showed mutations in TTC37, which encodes the uncharacterized tetratricopeptide repeat protein, thespin. Bioinformatic analysis suggested thespin to be involved in protein-protein interactions or chaperone. Preliminary studies of enterocyte brush-border ion transporter proteins (sodium hydrogen exchanger 2, sodium hydrogen exchanger 3, aquaporin 7, sodium iodide symporter, and hydrogen potassium adenosine triphosphatase [ATPase]) showed reduced expression or mislocalization in all THES patients with different profiles for each. In contrast the basolateral localization of Na/K ATPase was not altered.

CONCLUSIONS

THES is caused by mutations in TTC37. TTC37 mutations have a multisystem effect, which may be owing to abnormal stability and/or intracellular localization of TTC37 target proteins.

Tricho-hepato-enteric syndrome presenting with mild colitis

INTRODUCTION

A four and half-year-old girl was admitted to our clinic with the complaints of diarrhea since birth and failure to thrive.

DISCUSSION

The characteristic findings in physical examination were facial dysmorphism, hepatomegaly, and wooly hair. Trichorrhexis nodosa was established in microscopic hair examination. Colonoscopy and histopathologic examination of colonic mucosa revealed mild colitis. In the light of previously published cases, this patient was accepted as a mild variant of syndromic (phenotypic) diarrhea or tricho-hepato-enteric syndrome. We conclude that a mild phenotypic variant of this disease exists that may present with colitis.