Association of Adams-Oliver syndrome and hepatoportal sclerosis: an additional case

Evolving Understanding of Noncirrhotic Portal Hypertension

Although cirrhosis is one of the most common causes of portal hypertension, noncirrhotic portal hypertension can result from hemodynamic perturbations occurring in the prehepatic, intrahepatic, and posthepatic circulation. Intrahepatic portal hypertension can be further subclassified relative to the hepatic sinusoids as presinusoidal, sinusoidal, and postsinusoidal. For many of these differential diagnoses, the etiology is known but the cause of idiopathic noncirrhotic portal hypertension, recently included in porto-sinusoidal vascular disease (PSVD), remains poorly understood. Herein, we discuss the diagnostic pathological features of noncirrhotic portal hypertension, with an emphasis on PSVD.

Paediatric porto-sinusoidal vascular disease: Two different clinical phenotypes with subtle histological differences

BACKGROUND AND AIMS

In paediatrics, porto-sinusoidal vascular disease (PSVD) is relatively unknown and probably underdiagnosed. We aimed to describe clinical phenotypes, histology and outcome of children diagnosed with PSVD.

METHODS

Retrospective multicentre study of children diagnosed with PSVD. Diagnosis of PSVD was based on histopathology reports; liver specimens were re-evaluated by two expert liver pathologists.

RESULTS

Sixty two children diagnosed with PSVD (M/F = 36/26, median age 6.6 years, range 3.3-10.6), from 7 centres, were included. Thirty-six presented with non-cirrhotic portal hypertension, PH, (PH-PSVD Group = 58%) while 26 had a liver biopsy because of chronic elevation of transaminases without PH (noPH-PSVD Group = 42%). On histology review, the two groups differed for the prevalence of obliterative portal venopathy (more prevalent in PH-PSVD, p = 0.005), and hypervascularised portal tracts (more common in noPH-PSVD, p = 0.039), the other histological changes were equally distributed. At multivariate analysis, platelet count ≤185 000/mm³ was the only independent determinant of PH (p < 0.001). After a median follow-up of 7 years (range 3.0-11.2), in PH-PSVD group 3/36 (8%) required TIPS placement, 5/36 (14%) developed pulmonary vascular complications of PH, and 7/36 (19%) required liver transplantation. In noPH-PSVD none progressed to PH nor had complications.

CONCLUSIONS

Paediatric patients with PSVD present with two different clinical phenotypes, one characterised by PH and one by chronic elevation of transaminases without PH. PSVD should be included among the conditions causing isolated hypertransaminasaemia. On histology, the differences between the two groups are subtle. Medium-term outcome is favourable in patients without PH; progression of the disease is observed in those with PH.

Adams-Oliver syndrome review of the literature: Refining the diagnostic phenotype

The Adams-Oliver syndrome (AOS) is defined as aplasia cutis congenita (ACC) with transverse terminal limb defects (TTLD). Frequencies of associated anomalies are not well characterized. Six causative genes have been identified: ARHGAP31, DOCK6, EOGT, RBPJ, NOTCH1, and DLL4. We review 385 previously described individuals (139 non-familial and 246 familial probands and family members) and add clinical data on 13 previously unreported individuals with AOS. In addition to ACC and TTLD, the most commonly associated anomalies included a wide variety of central nervous system (CNS) anomalies and congenital heart defects each seen in 23%. CNS anomalies included structural anomalies, microcephaly, vascular defects, and vascular sequelae. CNS migration defects were common. Cutis marmorata telangiectasia congenita (CMTC) was found in 19% of the study population and other vascular anomalies were seen in 14%. Hemorrhage was listed as the cause of death for five of 25 deaths reported. A relatively large number of non-familial probands were reported to have hepatoportal sclerosis with portal hypertension and esophageal varices. Non-familial probands were more likely to have additional anomalies than were familial probands. The data reported herein provide a basis for refining the diagnostic features of AOS and suggest management recommendations for probands newly diagnosed with AOS. © 2017 Wiley Periodicals, Inc.

Diffuse angiopathy in Adams-Oliver syndrome associated with truncating DOCK6 mutations

Adams-Oliver syndrome (AOS) is a rare malformation syndrome characterized by the presence of two anomalies: aplasia cutis congenita of the scalp and transverse terminal limb defects. Many affected individuals also have additional malformations, including a variety of intracranial anomalies such as periventricular calcification in keeping with cerebrovascular microbleeds, impaired neuronal migration, epilepsy, and microcephaly. Cardiac malformations can be present, as can vascular dysfunction in the forms of cutis marmorata telangiectasia congenita, pulmonary vein stenoses, and abnormal hepatic microvasculature. Elucidated genetic causes include four genes in different pathways, leading to a model of AOS as a multi-pathway disorder. We identified an infant with mild aplasia cutis congenita and terminal transverse limb defects, developmental delay and a severe, diffuse angiopathy with incomplete microvascularization. Whole-genome sequencing documented two rare truncating variants in DOCK6, a gene associated with a type of autosomal recessive AOS that recurrently features periventricular calcification and impaired neurodevelopment. We highlight an unexpectedly high frequency of likely deleterious mutations in this gene in the general population, relative to the rarity of the disease, and discuss possible explanations for this discrepancy.

Hepatoportal sclerosis in childhood: descriptive analysis of 12 patients

Hepatoportal sclerosis (HPS) is defined as sclerosis of portal areas in the absence of cirrhosis. There is little information about HPS in children in the literature. The aim of this study was to describe the clinical presentation, associated disorders, laboratory characteristics and outcome of children who were diagnosed as HPS. This study included 12 children diagnosed as HPS by the Pathology Department between 2005 and 2011. Data were collected from the gastroenterology clinic charts retrospectively, including demographics, presentation characteristics, laboratory data and recent status of patients. Twelve patients were enrolled (6 girls, 6 boys). The median age of patients was 13.5 yr. Median age at the time of biopsy was 11 yr. Four patients had splenomegaly, 3 had esophageal varices, one had hepatopulmonary syndrome and had been transplanted. Smooth muscle antibody was found positive in 4 patients, without autoimmune hepatitis findings in liver biopsy. One patient had celiac disease and another patient had positive celiac disease serology but pathology findings. Another patient had Turner's syndrome. Mean follow-up time was 39 months (3.3 yr) after biopsy. Hepatoportal sclerosis does not necessarily present with portal hypertension in children.

Controllable inhibition of hepatitis B virus replication by a DR1-targeting short hairpin RNA (shRNA) expressed from a DOX-inducible lentiviral vector

As a highly efficient delivery system, lentiviral vectors (LVs) have become a powerful tool to assess the antiviral efficacy of RNA drugs such as short hairpin RNA (shRNA) and decoys. Furthermore, recent advanced systems allow controlled expression of the effector RNA via coexpression of a tetracycline/doxycycline (DOX) responsive repressor (tTR-KRAB). Herein, this system was utilized to assess the antiviral effects of LV-encoded shRNAs targeting three conserved regions on the pregenomic RNA of hepatitis B virus (HBV), namely the region coding for the reverse transcriptase (RT) domain of the viral polymerase (LV-HBV-shRNA1), the core promoter (CP; LV-HBV-shRNA2), and the direct repeat 1 (DR1; LV-HBV-shRNA3). Transduction of just the LV-HBV-shRNA vectors into the stably HBV expressing HepG2.2.15 cell line showed significant reductions in secreted HBsAg and HBeAg, intracellular HBcAg as well as HBV RNA and DNA replicative intermediates for all vectors, however, most pronouncedly for the DR1-targeting shRNA3. The corresponding vector was therefore applied in the DOX-controlled system. Notably, strong interference with HBV replication was found in the presence of the inducer DOX whereas the antiviral effect was essentially ablated in its absence; hence, the silencing effect of the shRNA and consequently HBV replication could be strictly regulated by DOX. This newly established system may therefore provide a valuable platform to study the antiviral efficacy of RNA drugs against HBV in a regulated manner, and even be applicable in vivo.

Adams-Oliver syndrome and portal hypertension: fortuitous association or common mechanism?

Adams-Oliver syndrome (AOS) is a rare condition defined by combination of cutis aplasia and transverse limb abnormalities. Some authors have described a possible association between this syndrome and portal hypertension (PH) due to hepatoportal sclerosis (HPS). We present a boy with AOS who developed a progressive splenomegaly and hypersplenism at the age of 2 months, and was admitted for acute gastrointestinal bleeding (GI) at the age of 9 months. Subsequently, we documented an extrahepatic portal vein obstruction and esophageal varices. After several episodes of cataclysmic upper GI bleeding a mesentero-portal shunt (MPS) was performed at 10 months. The shunt thrombosed, and after three failed attempts of thrombectomy, it was removed. One month later a splenorenal shunt was performed, and this closed spontaneously by 3 years. The patient suffered from ischemic stroke after placing the first shunt, and has spastic diplegia, left frontal lobe epilepsy, hyperactivity and attention deficit disorder, and severe psychomotor delay. At 11 years and he presented with chronic liver failure and hyperammonemia and coagulopathy. We hypothesize that there may be an early embryonic vascular abnormality (vascular disruption) that may explain these vascular phenomena.

The spectra of clinical phenotypes in aplasia cutis congenita and terminal transverse limb defects

The combination of aplasia cutis congenita (ACC) and terminal transverse limb defects (TTLD) is often referred to as the eponymous Adams-Oliver syndrome (AOS). The molecular basis of this disorder remains unknown, although the common occurrence of cardiac and vascular anomalies suggests a primary defect of vasculogenesis. Through the description of three previously unreported affected individuals, ascertained through the Adams-Oliver Syndrome European Consortium, we illustrate the phenotypic variability characteristically observed within extended families with AOS. Taken in combination with a detailed review of the available literature, we provide evidence for distinct clinical entities within the ACC/TTLD spectrum, which may reflect genetic heterogeneity within this spectrum of disorders.

Adams-Oliver syndrome: further evidence of an autosomal recessive variant

Adams-Oliver syndrome is characterized by aplasia cutis congenita and variable degrees of terminal transverse limb defects. Other associated anomalies were described in the syndrome. Most described cases follow an autosomal dominant pattern of inheritance. Sporadic and autosomal recessive cases, however, were reported. In this study, we report on three Egyptian patients with Adams-Oliver syndrome from three different families. The parents were normal and consanguineous in all three families. There was history of similarly affected sibs for two cases. These findings denote autosomal recessive inheritance. The reported cases had typical skull and limb anomalies with cutis marmorata telangiectatica congenita. We observed additional rare manifestations in the form of microcephaly, psychomotor retardation, epilepsy, eye anomalies and atrophic skin lesions. MRI of the brain in one of the studied cases revealed retrocerebellar cyst and mild asymmetrical cerebellar hypoplasia, which to our knowledge, were not previously reported in Adams-Oliver syndrome. The results of this study provide further evidence of clinical and genetic heterogeneity and support the presence of autosomal recessive variant of Adams-Oliver syndrome.

Clinical characteristics of idiopathic portal hypertension

Idiopathic portal hypertension is one of the interesting causes of portal hypertension. Even in very developed medical centers, this disorder is still one of the most important misdiagnoses of clinical practice. To inexperienced physicians, presenting esophageal varices and upper gastrointestinal bleeding usually prompt an unfortunate diagnosis of cirrhosis. A heterogenous clinical presentation and progression of this disorder should be recognized by physicians, and management should be directed towards some specific problems confined to this disorder. Although a genetic basis and other factors are implicated in its pathogenesis, exact underlying mechanism(s) is (are) unknown. In this review, we discuss the heterogeneity of idiopathic portal hypertension, its etiopathogenesis, clinical presentation and management issues. With the expectation of an excellent prognosis, a practicing gastroenterologist should be aware that “not all varices mean cirrhosis”.