Whole genome sequencing in ROHHAD trios proved inconclusive: what's beyond?

Rapid-onset Obesity with Hypothalamic dysfunction, Hypoventilation and Autonomic Dysregulation (ROHHAD) is a rare, life-threatening, pediatric disorder of unknown etiology, whose diagnosis is made difficult by poor knowledge of clinical manifestation, and lack of any confirmatory tests. Children with ROHHAD usually present with rapid onset weight gain which may be followed, over months or years, by hypothalamic dysfunction, hypoventilation, autonomic dysfunction, including impaired bowel motility, and tumors of neural crest origin. Despite the lack of evidence of inheritance in ROHHAD, several studies have been conducted in recent years that have explored possible genetic origins, with unsuccessful results. In order to broaden the search for possible genetic risk factors, an attempt was made to analyse the non-coding variants in two trios (proband with parents), recruited in the Gaslini Children's Hospital in Genoa (Italy). Both patients were females, with a typical history of ROHHAD. Gene variants (single nucleotide variants, short insertions/deletions, splice variants or in tandem expansion of homopolymeric tracts) or altered genomic regions (copy number variations or structural variants) shared between the two probands were searched. Currently, we have not found any potentially pathogenic changes, consistent with the ROHHAD clinical phenotype, and involving genes, regions or pathways shared between the two trios. To definitively rule out the genetic etiology, third-generation sequencing technologies (e.g., long-reads sequencing, optical mapping) should be applied, as well as other pathways, including those associated with immunological and autoimmune disorders, should be explored, making use not only of genomics but also of different -omic datasets.

Novel NALCN biallelic truncating mutations in siblings with IHPRF1 syndrome.

Infantile hypotonia with psychomotor retardation and characteristic facies-1 (IHPRF1) is a severe autosomal recessive neurologic disorder with onset at birth or in early infancy. It is caused by mutations in the NALCN gene that encodes a voltage-independent, cation channel permeable to NM, K+ and Ca2+ and forms a channel complex with UNCSO and UNC79. So far, only 4 homozygous mutations have been found in 11 cases belonging to 4 independent consanguineous families. We studied a Sardinian family with 2 siblings presenting dysmorphic facies, hypotonia, psychomotor retardation, epilepsy, absent speech, sleep disturbance, hyperkinetic movement disorder, cachexia and chronic constipation. Polymorphic generalized seizures started at 4 and 6 years, respectively. Anti-epileptic drugs (AEDs) therapy was efficient for female proband's epilepsy, but the male still has weekly seizures. Whole exome sequencing identified 2 novel truncating mutations in NALCN allowing to assess the clinical phenotype to IHPRF1. This is the fifth family reported worldwide, and these are the first European cases with IHPRF1 syndrome with biallelic truncating mutations of NALCN.

Laparoscopic Biopsies in Pancreas Transplantation.

As there is no precise laboratory test or imaging study for detection of pancreas allograft rejection, there is increasing interest in obtaining pancreas tissue for diagnosis. Pancreas allograft biopsies are most commonly performed percutaneously, transcystoscopically, or endoscopically, yet pancreas transplant surgeons often lack the skills to perform these types of biopsies. We have performed 160 laparoscopic pancreas biopsies in 95 patients. There were 146 simultaneous kidney-pancreas biopsies and 14 pancreas-only biopsies due to pancreas alone, kidney loss, or extraperitoneal kidney. Biopsies were performed for graft dysfunction (89) or per protocol (71). In 13 cases, an additional laparoscopic procedure was performed at the same operation. The pancreas diagnostic tissue yield was 91.2%; however, the pancreas could not be visualized in eight cases (5%) and in 6 cases the tissue sample was nondiagnostic (3.8%). The kidney tissue yield was 98.6%. There were four patients with intraoperative complications requiring laparotomy (2.5%) with two additional postoperative complications. Half of all these complications were kidney related. There were no episodes of pancreatic enzyme leak and there were no graft losses related to the procedure. We conclude that laparoscopic kidney and pancreas allograft biopsies can be safely performed with very high tissue yields.

Treatment of HCC in patients awaiting liver transplantation.

Liver transplantation (LT) is the treatment of choice for many patients with unresectable hepatocellular carcinoma (HCC), but long waiting time due to the shortage of donor organs can result in tumor progression and drop-out from LT candidacy. Furthermore, even in candidates meeting the restrictive Milan criteria there is risk of HCC recurrence; this risk rises significantly when patients with more advanced HCC are included. In an effort to address these issues, treatment of HCC in patients awaiting LT has become widespread practice. In this review the various modalities employed in the pre-LT setting are presented, and the evidence for benefit with regard to (1) improvement of post-LT survival, (2) down-staging of advanced HCC to within Milan criteria and (3) preventing waiting list drop-out is considered. Chemoembolization, radiofrequency ablation and ethanol injection all have well-documented antitumor activity; however, there is no high level evidence that waiting list HCC treatment with these modalities is effective in achieving any of the three above-mentioned aims. Nevertheless, particularly in the United States, where continued waiting list priority depends on maintaining HCC within Milan criteria, use of nonsurgical HCC treatment will likely continue in an effort to forestall tumor progression and waiting list drop-out.