Achalasia familiar: report of a family with an autosomal dominant pattern of inherence

Familial achalasia isolated or syndromic: about 18 families

Aim: Familial achalasia (FA) is a very rare condition. This work aims to evaluate its prevalence, characterize its clinical profile in a large series, and assess the efficacy and safety of pneumatic dilation (PD) in this context. Methods: A total of 817 patients with achalasia were collected over a period of 20 years (1990–2010). All cases of FA: isolated or associated to Allgrove syndrome, were looked for in both parents and siblings. Results: In this study, 18 families with FA were identified n = 41 patients (5%). Two members were affected in each family, in 14 families, three members per family in three others, and for the remaining family 04 members. All cases of achalasia were observed in siblings and parent to child transmission was unfound. Achalasia was associated to Allgrove syndrome in 15 families. It was isolated in 3 families. Consanguinity was found in 89% of patients, and death at a young age in the siblings was recorded in 27% of cases. Achalasia was present before the age of 5 years in 75% of cases. There was no difference between the two groups for age, age at onset, sex and the presence of the cardinal signs of achalasia. A total of 102 dilations were performed. Only one session in 31% of cases, two in 38%, three in 17% and more than three sessions in 14%. The long-term success rate of PD was low. Conclusions: FA manifests almost exclusively in childhood. It is rarely isolated; most often falls under Allgrove syndrome. Alacrima is the earliest sign that should lead to the diagnosis. The long-term success rate of PD is rather low. This requires recourse to multiple sessions of PD or Heller’s cardiomyotomy which may be the best initial approach.

Transient receptor potential ion channel function in sensory transduction and cellular signaling cascades underlying visceral hypersensitivity

Visceral hypersensitivity is an important mechanism underlying increased abdominal pain perception in functional gastrointestinal disorders including functional dyspepsia, irritable bowel syndrome, and inflammatory bowel disease in remission. Although the exact pathophysiological mechanisms are poorly understood, recent studies described upregulation and altered functions of nociceptors and their signaling pathways in aberrant visceral nociception, in particular the transient receptor potential (TRP) channel family. A variety of TRP channels are present in the gastrointestinal tract (TRPV1, TRPV3, TRPV4, TRPA1, TRPM2, TRPM5, and TRPM8), and modulation of their function by increased activation or sensitization (decreased activation threshold) or altered expression in visceral afferents have been reported in visceral hypersensitivity. TRP channels directly detect or transduce osmotic, mechanical, thermal, and chemosensory stimuli. In addition, pro-inflammatory mediators released in tissue damage or inflammation can activate receptors of the G protein-coupled receptor superfamily leading to TRP channel sensitization and activation, which amplify pain and neurogenic inflammation. In this review, we highlight the present knowledge on the functional roles of neuronal TRP channels in visceral hypersensitivity and discuss the signaling pathways that underlie TRP channel modulation. We propose that a better understanding of TRP channels and their modulators may facilitate the development of more selective and effective therapies to treat visceral hypersensitivity.

Simultaneous diagnosis of familial achalasia: report of two cases

Background

Achalasia is a rare disease with a morbidity of 1 in 100,000, for which the exact mechanism of pathogenesis has not been clarified due to the small total number of patients. We herein report on our experience with two cases of familial achalasia in which the involvement of genetic inheritance was suspected.

Case presentation

These cases consist of a man in his thirties and his mother in her sixties. The son consulted the Department of Gastrointestinal Medicine at our institute with dysphagia, and an upper gastrointestinal endoscopy revealed a gastric submucosal tumor with a maximal diameter of approximately 50 mm. Achalasia was also strongly suspected due to the enlargement of the esophagus to the maximum transverse diameter of 55 mm by esophagography along with delayed clearance of barium. A detailed interview revealed prolonged mild dysphagia in his mother. Therefore, high-resolution manometry was carried out in both patients. As a result, peristaltic disorder was observed in the esophageal body in both the mother and son, leading to a definitive diagnosis of achalasia. For the son, total gastrectomy including the lower esophagus with Roux-en-Y reconstruction was performed. His postoperative course was uneventful, and the patient was discharged from hospital in remission on the 9th day following surgery and is currently undergoing follow-up as an outpatient.

Conclusions

We hereby report on a very rare case of familial achalasia that we experienced which may suggest a genetic element in the onset of achalasia, and reviewed the literature.

Gene expression of muscular and neuronal pathways is cooperatively dysregulated in patients with idiopathic achalasia

Idiopathic achalasia is characterized by the absence of peristalsis secondary to loss of neurons in the myenteric plexus that hampers proper relaxation of the lower esophageal sphincter. Achalasia can be considered a multifactorial disorder as it occurs in related individuals and is associated with HLA class II genes, thereby suggesting genetic influence. We used microarray technology and advanced in-silico functional analyses to perform the first genome-wide expression profiling of mRNA in tissue samples from 12 achalasia and 5 control patients. It revealed 1,728 differentially expressed genes, of these, 837 (48.4%) were up-regulated in cases. In particular, genes participating to the smooth muscle contraction biological function were mostly up-regulated. Functional analysis revealed a significant enrichment of neuronal/muscular and neuronal/immunity processes. Upstream regulatory analysis of 180 genes involved in these processes suggested TLR4 and IL18 as critical key-players. Two functional gene networks were significantly over-represented: one involved in organ morphology, skeletal muscle system development and function, and neurological diseases, and the other participating in cell morphology, humoral immune response and cellular movement. These results highlight on pivotal genes that may play critical roles in neuronal/muscular and neuronal/immunity processes, and that may contribute to the onset and development of achalasia.

Allele-specific transcriptional activity of the variable number of tandem repeats of the inducible nitric oxide synthase gene is associated with idiopathic achalasia

BACKGROUND

Polymorphisms of genes involved in the regulation of the immune response are risk factors for achalasia, but their contribution to disease pathogenesis is unknown. Nitric oxide is involved both in immune function and inhibitory neurotransmission.

OBJECTIVE

The objective of this article is to assess the association and the functional relevance of the CCTTT-inducible nitric oxide synthase (NOS2) gene promoter polymorphism in achalasia.

METHODS

Genomic DNA was isolated from 181 achalasia patients and 220 controls. Genotyping of the (CCTTT)n repeats was performed by PCR and capillary electrophoresis, and data analyzed by considering the frequency of the different alleles. HT29 cells were transfected with iNOS luciferase promoter-reporter plasmids containing different (CCTTT)n.

RESULTS

The alleles' distribution ranged from 7 to 18, with a peak frequency at 12 repeats. Analysis of the allele frequencies revealed that individuals carrying 10 and 13 CCTTT repeats were respectively less and more frequent in achalasia (OR 0.5, 95% CI 0.3-0.5 and OR 1.6, 95% CI 1-2.4, all p < 0.05). Long repeats were also significantly associated with an earlier onset of the disease (OR 1.69, 95% CI 1.13-2.53, p = 0.01). Transfection experiments revealed a similar allele-specific iNOS transcriptional activity.

CONCLUSION

The functional polymorphism (CCTTT) of NOS2 promoter is associated with achalasia, likely by an allele-specific modulation of nitric oxide production.

Genetic variation in the lymphotoxin-α (LTA)/tumour necrosis factor-α (TNFα) locus as a risk factor for idiopathic achalasia

BACKGROUND

Idiopathic achalasia is a rare motor disorder of the oesophagus characterised by neuronal loss at the lower oesophageal sphincter. Achalasia is generally accepted as a multifactorial disorder with various genetic and environmental factors being risk-associated. Since genetic factors predisposing to achalasia have been poorly documented, we assessed whether single nucleotide polymorphisms (SNPs) in genes mediating immune response and neuronal function contribute to achalasia susceptibility.

METHODS

391 SNPs covering 190 immune and 67 neuronal genes were genotyped in an exploratory cohort from Central Europe (589 achalasia patients, 794 healthy volunteers (HVs)). 24 SNPs (p<0.05) were validated in an Italian (160 achalasia patients, 278 HVs) and Spanish cohort (281 achalasia patients, 296 HVs). 16 SNPs in linkage disequilibrium (LD) with rs1799724 (r(2)>0.2) were genotyped in the exploratory cohort. Genotype distributions of patients (1030) and HVs (1368) were compared using Cochran-Armitage trend test.

RESULTS

The rs1799724 SNP located between the lymphotoxin-α (LTA) and tumour necrosis factor-α (TNFα) genes was significantly associated with achalasia and withstood correction for testing multiple SNPs (p=1.17E-4, OR=1.41 (1.18 to 1.67)). SNPs in high LD with rs1799724 were associated with achalasia. Three SNPs located in myosin-5B, adrenergic receptor-β-2 and interleukin-13 (IL13) showed nominally significant association to achalasia that was strengthened by replication.

CONCLUSIONS

Our study provides evidence for rs1799724 at the LTA/TNFα locus as a susceptibility factor for idiopathic achalasia. Additional studies are needed to dissect which genetic variants in the LTA/TNFα locus are disease-causing and confirm other variants as potential susceptibility factors for achalasia.