Unusual occurrence of intestinal pseudo obstruction in a patient with maternally inherited diabetes and deafness (MIDD) and favorable outcome with coenzyme Q10

Gastrointestinal involvement in neuromuscular disorders

Although not often discussed, many of the neuromuscular disorders (NMDs) affect the gastrointestinal tract (GIT). Depending on the type of NMD, the prevalence of GIT involvement ranges from <5% (e.g. hereditary neuropathies, myofibrillar myopathies) to 100% (e.g. MNGIE, OPMD). Particularly in NMDs with multisystem affection, involvement of the GIT can dominate the clinical presentation or at least make up a significant part of the clinical picture. The most prominent representatives of NMDs with multisystem involvement are the mitochondrial disorders (MIDs) and the myotonic dystrophies. The best known syndromic MIDs with GIT involvement are MNGIE, MELAS, Leigh, and Pearson syndromes. Among neuropathies, GIT involvement is most commonly found in ALS and GBS. GIT involvement may also be a feature of myasthenia. The clinical manifestations of GIT involvement are diverse and can affect the entire GIT, from the teeth to the rectum, including the liver and pancreas. The most well-known clinical manifestations of GIT involvement are dysphagia, nausea, vomiting, reflux, hollow organ dysmotility, hepatopathy, diabetes, diarrhea, constipation, and fecal incontinence. Even if treatment can usually only be symptomatic, the therapeutic options are diverse, are often effective, and can significantly and beneficially influence the course of the underlying NMD.

Gut dysmotility in children with neurological impairment: the nutritional management

Intestinal motility disorders represent a frequent problem in children with neurological impairment. These conditions are characterized by abnormal movements of the gut, which can result in symptoms such as constipation, diarrhea, reflux, and vomiting. The underlying mechanisms leading to dysmotility are various, and the clinical manifestations are often nonspecific. Nutritional management is an important aspect of care for children with gut dysmotility, as it can help to improve their quality of life. Oral feeding, when safe and in the absence of risk of ingestion or severe dysphagia, should always be encouraged. When oral nutrition is insufficient or potentially harmful, it is necessary to switch to an enteral by tube or parenteral nutrition before the onset of malnutrition. In most cases, children with severe gut dysmotility may require feeding via a permanent gastrostomy tube to ensure adequate nutrition and hydration. Drugs may be necessary to help manage gut dysmotility, such as laxatives, anticholinergics and prokinetic agents. Nutritional management of patients with neurological impairment often requires an individualized care plan to optimize growth and nutrition and to improve overall health outcomes. This review tries to sum up most significant neurogenetic and neurometabolic disorders associated with gut dysmotility that may require a specific multidisciplinary care, identifying a proposal of nutritional and medical management.

Chronic intestinal psuedo-obstruction and MIDD, a rare cause of acute abdomen: implications in emergency surgery

Chronic intestinal pseudo-obstruction (CIPO) is a condition typified by the failure of the small bowel to propel contents in the absence of physical obstruction. CIPO is diagnosed after eliminating other causes, presenting a diagnostic challenge in emergency surgery. We report a case of a 32-year-old man with a rare mitochondrial disorder, Maternally inherited diabetes and deafness (MIDD), who presented to our hospital acutely unwell with peritonitis. Laparotomy revealed distended small bowel with no transition point, and turbid fluid with no macroscopic source. Postoperatively he had severe electrolyte and vitamin deficiencies. The diagnosis of CIPO leading to paralytic ileus and bacterial translocation was established and managed with aggressive electrolyte and vitamin replacement. He was discharged day 12 post operatively after a prolonged ileus with follow-up from a quaternary metabolic unit. We discuss here the challenges and gold standard in the emergency management of CIPO.

Case Report: Identification of a Novel Variant (m.8909T>C) of Human Mitochondrial ATP6 Gene and Its Functional Consequences on Yeast ATP Synthase

With the advent of next generation sequencing, the list of mitochondrial DNA (mtDNA) mutations identified in patients rapidly and continuously expands. They are frequently found in a limited number of cases, sometimes a single individual (as with the case herein reported) and in heterogeneous genetic backgrounds (heteroplasmy), which makes it difficult to conclude about their pathogenicity and functional consequences. As an organism amenable to mitochondrial DNA manipulation, able to survive by fermentation to loss-of-function mtDNA mutations, and where heteroplasmy is unstable, Saccharomyces cerevisiae is an excellent model for investigating novel human mtDNA variants, in isolation and in a controlled genetic context. We herein report the identification of a novel variant in mitochondrial ATP6 gene, m.8909T>C. It was found in combination with the well-known pathogenic m.3243A>G mutation in mt-tRNA^Leu. We show that an equivalent of the m.8909T>C mutation compromises yeast adenosine tri-phosphate (ATP) synthase assembly/stability and reduces the rate of mitochondrial ATP synthesis by 20-30% compared to wild type yeast. Other previously reported ATP6 mutations with a well-established pathogenicity (like m.8993T>C and m.9176T>C) were shown to have similar effects on yeast ATP synthase. It can be inferred that alone the m.8909T>C variant has the potential to compromise human health.

Diabetes, deafness and renal disease

Deafness, kidney disease and diabetes are not a usual association, neither is a family history of these diseases. We present the case of a 47-year-old woman with non-nephrotic proteinuria, no haematuria, normal renal function, sensorineural hearing loss, recently diagnosed diabetes and maculopathy. There was a maternal family history of deafness, diabetes and renal disease. Renal biopsy revealed focal and segmental glomerulosclerosis (FSGS), leading to the pursuit of an m.3243A > G mitochondrial mutation and diagnosis of maternally inherited diabetes and deafness. The association of FSGS with mitochondrial diseases is not well known among nephrologists. Its timely diagnosis is important to avoid exposure to ineffective and unnecessary immunosuppression.

Gastrointestinal manifestations of mitochondrial disorders: a systematic review

Mitochondrial disorders (MIDs) due to respiratory-chain defects or nonrespiratory chain defects are usually multisystem conditions [mitochondrial multiorgan disorder syndrome (MIMODS)] affecting the central nervous system (CNS), peripheral nervous system, eyes, ears, endocrine organs, heart, kidneys, bone marrow, lungs, arteries, and also the intestinal tract. Frequent gastrointestinal (GI) manifestations of MIDs include poor appetite, gastroesophageal sphincter dysfunction, constipation, dysphagia, vomiting, gastroparesis, GI pseudo-obstruction, diarrhea, or pancreatitis and hepatopathy. Rare GI manifestations of MIDs include dry mouth, paradontosis, tracheoesophageal fistula, stenosis of the duodeno-jejunal junction, atresia or imperforate anus, liver cysts, pancreas lipomatosis, pancreatic cysts, congenital stenosis or obstruction of the GI tract, recurrent bowel perforations with intra-abdominal abscesses, postprandial abdominal pain, diverticulosis, or pneumatosis coli. Diagnosing GI involvement in MIDs is not at variance from diagnosing GI disorders due to other causes. Treatment of mitochondrial GI disease includes noninvasive or invasive measures. Therapy is usually symptomatic. Only for myo-neuro-gastro-intestinal encephalopathy is a causal therapy with autologous stem-cell transplantation available. It is concluded that GI manifestations of MIDs are more widespread than so far anticipated and that they must be recognized as early as possible to initiate appropriate diagnostic work-up and avoid any mitochondrion-toxic treatment.

Maternally-inherited diabetes with deafness (MIDD) and hyporeninemic hypoaldosteronism

Maternally-inherited diabetes with deafness (MIDD) is a rare form of monogenic diabetes that results, in most cases, from an A-to-G transition at position 3243 of mitochondrial DNA (m.3243A>G) in the mitochondrial-encoded tRNA leucine (UUA/G) gene. As the name suggests, this condition is characterized by maternally-inherited diabetes and bilateral neurosensory hearing impairment. A characteristic of mitochondrial cytopathies is the progressive multisystemic involvement with the development of more symptoms during the course of the disease. We report here the case of a patient with MIDD who developed hyporeninemic hypoaldosteronism.

Clinical features and heteroplasmy in blood, urine and saliva in 34 Dutch families carrying the m.3243A > G mutation

The m.3243A>G mutation has become known as the MELAS mutation. However, many other clinical phenotypes associated with this mutation have been described,most frequently being Maternally Inherited Diabetes and Deafness (MIDD). The m.3243A>G mutation, can be detected in virtually all tissues, however heteroplasmy differs between samples. Recent reports indicate, a preference to perform mutation analysis in Urinary Epithelial Cells(UEC). To test this, and to study a correlation between the mutational load in different tissues with two mitochondrial scoring systems (NMDAS and NPMDS) we investigated 34 families carrying the m.3243A>G mutation. Heteroplasmy was determined in three non-invasively collected samples,namely leucocytes, UEC and buccal mucosa. We included 127 patients, of which 82 carried the m.3243A>G mutation.None of the children (n011) had specific complaints. In adults(n071), a median NMDAS score of 15 (IQR 10-24) was found. The most prevalent symptoms were hearing loss(68 %), gastro-intestinal problems (59 %), exercise intolerance(54 %) and glucose intolerance (52 %). Ten patients had neurologic involvement. Buccal mucosa had the best correlation with the NMDAS in all adults (r00.437, p<0.001),whereas UEC had the strongest correlation with the NMDAS in severely affected patients (r00.593, p00.002). Heteroplasmy declined significantly with increasing age in all three samples (leucocytes r0-0.705 (p<0.001), UEC r0-0.374 (p00.001), buccal mucosa r0-0.460 (p<0.001). In our cohort of 82 patients, the m.3243A>Gmutation causes a wide variety of signs and symptoms, MIDD being far more prevalent than MELAS. Looking at the characteristics of the three noninvasively available tissues for testing heteroplasmy we confirm that UEC are the preferred sample to test [corrected].

Is there a place for coenzyme Q in the management of metabolic disorders associated with obesity?

Coenzyme Q (CoQ), a lipophilic cofactor of the electron transport chain in the mitochondria, can be synthesized endogenously or provided by food. The aim of this review is to summarize the in vitro cell culture studies, the in vivo animal studies, and the human studies investigating the impact of CoQ supplementation on the occurrence of obesity and related disorders (diabetes, hypertension, lipemia, and atherosclerosis). The antioxidative properties of CoQ have been observed in different experimental models of atherosclerosis, obesity, and diabetes. The recent discovery of the anti-inflammatory effect of CoQ, mostly described in vitro, has generated increased interest in CoQ supplementation, but it needs to be confirmed in vivo in pathological situations. CoQ intervention studies in humans failed to show reproducible effects on body weight, fat mass, or glycemia, but CoQ supplementation does seem to have an antihypertensive effect. The molecular mechanism to explain this effect has only recently been discovered.

Clinical aspects of coenzyme Q10: an update

The fundamental role of coenzyme Q(10) (CoQ(10)) in mitochondrial bioenergetics and its well-acknowledged antioxidant properties constitute the basis for its clinical applications, although some of its effects may be related to a gene induction mechanism. Cardiovascular disease is still the main field of study and the latest findings confirm a role of CoQ(10) in improving endothelial function. The possible relation between CoQ(10) deficiency and statin side effects is highly debated, particularly the key issue of whether CoQ(10) supplementation counteracts statin myalgias. Furthermore, in cardiac patients, plasma CoQ(10) was found to be an independent predictor of mortality. Studies on CoQ(10) and physical exercise have confirmed its effect in improving subjective fatigue sensation and physical performance and in opposing exercise-related damage. In the field of mitochondrial myopathies, primary CoQ(10) deficiencies have been identified, involving different genes of the CoQ(10) biosynthetic pathway; some of these conditions were found to be highly responsive to CoQ(10) administration. The initial observations of CoQ(10) effects in Parkinson's and Huntington's diseases have been extended to Friedreich's ataxia, where CoQ(10) and other quinones have been tested. CoQ(10) is presently being used in a large phase III trial in Parkinson's disease. CoQ(10) has been found to improve sperm count and motility on asthenozoospermia. Moreover, for the first time CoQ(10) was found to decrease the incidence of preeclampsia in pregnancy. The ability of CoQ(10) to mitigate headache symptoms in adults was also verified in pediatric and adolescent populations.