Francesca Menni

Glucose metabolism and diet-based prevention of liver dysfunction in MPV17 mutant patients

BACKGROUND/AIMS To describe in detail the specific clinical and biological characteristics of three patients with MPV17 gene mutations, a rare hepatocerebral mitochondrial DNA depletion syndrome (MDS) and the positive effects of a novel dietetic treatment based on avoidance of fasting. METHODS We describe the case histories of three members of the same family with MPV17 mutations. RESULTS Two patients had a very severe and progressive liver disease: 1 died in the first year of life and the other underwent liver transplantation. The third patient, now 13 years of age, had a milder form of liver disease and developed progressive ataxia. Psychomotor involvement at onset of disease was mild or absent. No patient had severe hyperlactataemia. In vivo functional studies on two patients showed no hyperlactataemia even after intravenous and oral glucose loading, regular fasting hypoglycemia 3-4h after meals and no response to glucagon. Liver function tests improved when patients received continuous iv glucose infusion or were regularly fed every 3h. CONCLUSIONS These clinical and biochemical features allow us to differentiate patients with MPV17 mutations from other liver MDS and suggest that regular glucose intake at short intervals may be beneficial in slowing the progression of the disease.

Is it time to change the neurofibromatosis 1 diagnostic criteria

Neurofibromatosis 1 is a complex inherited neurocutaneous disease that is often difficult to diagnose early because of its age-dependent presentation. The diagnosis is also extremely difficult to communicate to patients and their parents because of the diseases clinical variability, unpredictable evolution, and uncertain prognosis. Since 1988, the year of publication of the last Consensus Conference statement concerning the diagnosis of neurofibromatosis 1, our understanding of the disease has naturally increased and, in addition to the availability of increasingly precise molecular analyses, some new clinical signs have been reported such as anaemic nevi, unidentified bright objects, choroidal hamartomas, and a typical neuropsychological phenotype. We critically review the current diagnostic criteria, and suggest the addition of new signs on the basis of published findings and our own clinical experience. This proposal aims to improve diagnostic power in paediatric age, securing a better and more reliable healthcare transition toward adult age. We finally recommend a new Consensus Conference in order to revise the diagnostic criteria, possibly differentiated by age of presentation.

Rubinstein-Taybi syndrome: clinical features, genetic basis, diagnosis, and management

BackgroundRubinstein-Taybi syndrome (RSTS) is an extremely rare autosomal dominant genetic disease, with an estimated prevalence of one case per 125,000 live births. RSTS is characterized by typical facial features, microcephaly, broad thumbs and first toes, intellectual disability, and postnatal growth retardation. However, no standard diagnostic criteria are available for RSTS. In this review, we summarized the clinical features and genetic basis of RSTS and highlighted areas for future studies on an appropriate diagnostic protocol and follow-up care for RSTS.DiscussionRSTS is primarily characterized by delayed growth in height and weight, microcephaly, dysmorphic facial features, and broad thumbs and big toe. Over 90% RSTS individuals with disabilities survive to adulthood, but healthcare for these patients is particularly complex, time-consuming, and costly. In addition, no standard diagnostic criteria and follow-up care guidelines are available for RSTS. It has been shown that mutations in the genes encoding the cyclic-AMP-regulated enhancer binding protein (CREBBP) and the E1A-binding protein p300 (EP300) contributed to the development of RSTS. Therefore, genetic tests are useful for the diagnosis of RSTS, although most RSTS cases are currently diagnosed based on clinical features.SummaryThe clinical features of RSTS have been extensively studied, which significantly contributes to the diagnosis of this extremely rare syndrome. However, the pathogenesis and genotype-phenotype associations of RSTS are largely unknown. Therefore, multicenter studies and international cooperation are highlighted for better understanding of this disease, establishing standard diagnostic criteria, and providing professional management and follow-up care of RSTS.

Severe vitamin B12 deficiency in an exclusively breastfed 5-month-old Italian infant born to a mother receiving multivitamin supplementation during pregnancy

BackgroundIn infants, vitamin B12 deficiency may be due to an inborn error of absorption and metabolism, or nutritional problems.Case presentationAn exclusively breastfed 5-month-old Italian male infant, who was born after a normal full-term pregnancy to a vegan mother who was apparently daily treated with a multivitamin oral preparation during the second and third trimester, was hospitalised because of poor weight gain, feeding difficulties, severe pallor, muscle hypotonia and somnolence. Upon admission, his weight, length and head circumference were below the third percentile, he had an enlarged liver and spleen, and showed a significant delay in developmental milestones and communicative reactions. He had a hemoglobin level of 4.7 g/dL with an MCV of 84.2 fL, a white blood cell count of 4,680/mm3, and a platelet count of 45,000/mm3. His serum vitamin B12 level was 57 pg/mL (normal value 180–500 pg/mL) and serum folate level 12.8 ng/mL (normal value >3 ng/mL). The results of metabolic examinations excluded a cobalamin C disorder, whereas nutritional screening showed a serum iron concentration of 9 μg/dL and serum ferritin of 4 ng/mL. Magnetic resonance imaging of the brain showed mild dilatation of the lateral ventricles with diffuse delayed myelination. The child was diagnosed as having vitamin B12 and iron deficiency due to nutritional inadequacy and was immediately treated with packed red blood cells, intramuscular vitamin B12 injections, and iron supplementation. A few days after the start of therapy, his hemoglobin levels and other hematological parameters rapidly improved, and a clinical improvement was observed within few weeks. There was an increase in his achievement of developmental milestones, but his development was still retarded seven months after the start of therapy.ConclusionThis case underlines the importance of adequately controlling maternal vitamin B12 intake during pregnancy by means of supplementation which, in the case of vegan mothers, should be significantly greater than that usually given. Moreover, the supplementation should be continued during lactation in order to avoid the development of signs of deficiency that may be associated with persistent neurological problems in infants. The case also highlights the need to consider vitamin B12 deficiency in infants with severe anemia even if their hematological parameters do not indicate megaloblastic anemia because the concomitant presence of substantial iron deficiency may modify the characteristics of the anemia.

Combined liver-kidney transplantation in glycogen storage disease Ia: A case beyond the guidelines†

Glycogen storage disease type Ia (GSD Ia) is a rare metabolic disorder due to hepatic glucose‐6‐phosphatase deficiency. Although great progress has been made in managing affected patients, severe hypoglycemia, lactic acidosis, hyperlipidemia, hepatic cytolysis, and impaired kidney function are frequent. Liver transplantation is the only radical treatment, for which the main indications are hepatic adenomatosis, hepatocellular carcinoma, or severe hepatic dysfunction. We present the case of a patient with end‐stage renal disease without focal hepatic lesions and with moderate hepatic metabolic control, and we explain how combined liver‐kidney transplantation (LKT) made it possible to correct the metabolic defects responsible for the impaired glucose homeostasis, liberalize the diet, and give birth to a healthy child after an uneventful pregnancy. Patients with end‐stage renal disease that resulted from GSD Ia should be considered for LKT even in the absence of hepatic lesions with the aim of improving their quality of life. Liver Transpl 13:762–764, 2007.

Acute, severe cardiomyopathy as main symptom of late-onset very long-chain acyl-coenzyme A dehydrogenase deficiency.

AbstractA 5-year-old boy with late-onset very long-chain acyl-CoA-dehydrogenase (VLCAD) deficiency presented with acute cardiomyopathy, myopathy, gross myoglobinuria and normoglycaemia. The clinical course after diagnosis was favourable. Conclusion late-onset VLCAD deficiency may present as acute cardiomyopathy.

Healthcare transition in patients with rare genetic disorders with and without developmental disability: neurofibromatosis 1 and Williams-Beuren syndrome.

There are between 5,000 and 8,000 distinct rare diseases (RDs) affecting 6–8% of the population, most of which are caused by genetic defects. Many are highly complex, childhood‐onset, multi‐system disorders that are often associated with developmental disability, and require lifelong, highly specialized care and support. As larger numbers of children with previously fatal RDs survive into adulthood, they encounter significant challenges in transitioning from family‐centered, developmentally focused, multidisciplinary pediatric care to a less supportive adult healthcare system that is often unfamiliar with these conditions. This paper discusses the challenges of the transition from pediatric to adult health care in two groups of patients with multisystem genetic RDs (neurofibromatosis 1 [NF1] and Williams–Beuren syndrome [WBS]), and analyzes strategies for making the process easier for patients with and without developmental disabilities. Our findings show that there are still no guidelines in national healthcare programs on how to transition RD adolescents with and without developmental disabilities, and only a few pediatric centers have implemented the elements of transition in their general practice. Evidence regarding programs to facilitate transition is inconclusive and the transition from pediatric medicine to adult medicine for RDs remains a major challenge. However, transition requires both time and personnel, which are difficult to find in periods of fiscal austerity. Nevertheless, we should strongly advocate for governments investing more into transition infrastructure or they will face increased long‐term social and economic costs due to poor treatment compliance, disengagement from services, increased genetic risks, and higher rates of disease‐related complications.

Immunogenicity, safety and tolerability of monovalent 2009 pandemic influenza A/H1N1 MF59-adjuvanted vaccine in children and adolescents with williams or cornelia de lange syndrome

In some subjects with severe neurological diseases, a reduced immune response to seasonal influenza vaccine has been demonstrated. Patients with Williams or Cornelia de Lange syndrome frequently have abnormalities in neurodevelopment. This study has evaluated the immunogenicity, safety and tolerability of a monovalent 2009 pandemic influenza A/H1N1 MF59-adjuvanted vaccine in these subjects. Eighteen patients with Williams syndrome (ten males; mean age ± standard deviation [SD] 12.74 ± 4.49 years), 11 with Cornelia de Lange syndrome (six males; mean age 12.90 ± 4.85 years) and 30 age- and gender-matched healthy controls (16 males; mean age 12.49 ± 4.55 years), never vaccinated against influenza, received a dose of the vaccine between 1 and 30 November 2009. Four weeks later, the seroconversion rates in the three groups were between 72% and 80% and the seroprotection rates were 100%, with a similar increase in antibody levels. Two months later, most of the subjects remained seroconverted with no statistically significant difference between the groups, and about 94% of the patients with Williams syndrome, all of those with Cornelia de Lange syndrome and all of the healthy controls were still seroprotected. Safety and tolerability were very good, with no difference between the groups. None of the patients developed documented influenza during the study period. These results show that the immunogenicity, safety, and tolerability of a single dose of the monovalent 2009 pandemic influenza A/H1N1 MF59-adjuvanted vaccine in children and adolescents with Williams or Cornelia de Lange syndrome and moderate to severe mental disabilities is very good, and similar to that of healthy subjects.

Think About It FMR1 Gene Mosaicism

Fragile X syndrome (FXS) is one of the most frequent causes of mental retardation, intellectual disability, and autism. Most cases are the result of an expansion of the CGG trinucleotide repeat in the 5′ untranslated region of the FMR1 gene and the subsequent functional loss of the related protein. We describe the case of a 4-year-old boy who clinically presents mild psychomotor delay without any major clinical dysmorphisms. Molecular analysis of the FMR1 gene showed mosaicism in terms of size and methylation, with one normal and 1 fully mutated allele, which is very rare in this syndrome. Physicians should therefore consider a diagnosis of FXS even if the patient’s phenotype is mild. Although rare, diagnosing this condition has important consequences for the patient’s rehabilitation and the family planning of parents and relatives.

Vaccination in children with inborn errors of metabolism

Inborn errors of metabolism (IEMs) are a large group of very heterogeneous diseases, and the impact of the available vaccines on children with IEMs may vary depending on the childs metabolic characteristics. The main aim of this review is to re-analyse the administration of vaccines to such children in the light of the most recent data. As a whole, these indicate that children with stable or slowly progressing IEMs can receive the recommended schedules of all of the recommended vaccinations. However, vaccines should be administered more cautiously to children with IEMs associated with a significant risk of morbidity and/or mortality with catabolic events: i.e. under strict medical supervision, and only when the children are clinically well and their metabolic condition is acceptably controlled. Furthermore, a number of IEMs have been associated with immune deficiency although, in most cases, the immunological abnormalities disappear or are significantly reduced when the metabolic defect is corrected. The response to vaccines is therefore unpredictable, but it is reasonable to think that it may be inadequate in children with the most severe immune defects. In addition to defective protection, vaccines administered to children with IEM and severe immunodeficiency can actually cause the disease they were meant to prevent. This explains why experts suggest that vaccines based on live attenuated viruses should not be given to such children, although all of the other vaccines can be administered without limitation regardless of the type of immune defect. Nevertheless, only specific multicentre studies will make it possible to say when and how to use vaccines in children with different types of IEM in order to protect them from vaccine-preventable diseases without any risk of worsening their metabolic situation.