Severe Lactic Acidosis Caused by Thiamine Deficiency in a Child with Relapsing Acute Lymphoblastic Leukemia: A Case Report.

Lactic acidosis is characterized by an excessive production of lactic acid or by its impaired clearance. Thiamine deficiency is an uncommon cause of lactic acidosis, especially in countries where malnutrition is rare. We describe the case of a 5-year-old boy who presented with a central nervous system relapse of acute lymphoblastic leukemia. During the chemotherapy regimen, the patient developed drug-induced pancreatitis with paralytic ileus requiring prolonged glucosaline solution infusion. In the following days, severe lactic acidosis (pH 7.0, lactates 253 mg/dL, HCO3- 8 mmol/L) was detected, associated with hypoglycemia (42 mg/dL) and laboratory signs of acute liver injury. Due to the persistent hypoglycemia, the dextrose infusion was gradually increased. Lactates, however, continued to raise, so continuous venovenous hemodiafiltration was started. While lactates initially decreased, 12 h after CVVHDF suspension, they started to raise again. Assuming that it could have been caused by mitochondrial dysfunction due to vitamin deficiency after prolonged fasting and feeding difficulties, parenteral nutrition and thiamine were administered, resulting in a progressive reduction in lactates, with the normalization of pH during the next few hours. In the presence of acute and progressive lactic acidosis in a long-term hospitalized patient, thiamine deficiency should be carefully considered and managed as early as possible.

Long term follow-up in two siblings with Sengers syndrome: Case report.

BACKGROUND: Sengers syndrome is characterized by congenital cataract, hypertrophic cardiomyopathy, mitochondrial myopathy, and lactic acidosis associated with mutations in AGK gene. Clinical course ranges from a severe fatal neonatal form, to a more benign form allowing survival into adulthood, to an isolated form of congenital cataract. Thus far few reported cases have survived the second decade at their latest examination, and no natural history data are available for the disease. CASE PRESENTATION: Here we provide a 20-year follow-up in two siblings with a benign form of Sengers syndrome, expanding the phenotypical spectrum of the disease by reporting a condition of ovarian agenesis. CONCLUSION: To our knowledge, this report provides the first longitudinal data of Sengers syndrome patients.

Quality of life aspects of a low protein diet using GMP in patients with phenylketonuria.

OBJECTIVE: To assess some quality of life (QOL) aspects of a low protein diet, using glycomacropeptide (GMP) as a protein substitute in patients with phenylketonuria (PKU). METHODS: This was a multicentre, prospective observational cohort, study. Metabolic control, nutritional parameters, and dietary adherence were assessed in patients with PKU before (T0), and six months after (T6) starting a low protein diet using GMP. Selected items from the PKU-QOL questionnaire were used to assess patients' acceptance of their modified diet. RESULTS: 18 patients from three Italian Centres, completed the study. With the exception of LDL-cholesterol and vitamin 25OH-D concentrations, there were no differences between T0 and T6 in metabolic or nutritional parameters. Data suggested that patients have a good acceptance of protein substitutes containing GMP, probably because of their improved palatability. CONCLUSIONS: According to our patients' responses to items related to dietary regimen, GMP based protein substitutes do not appear to significantly affect QOL.

Expanded Newborn Screening in Italy Using Tandem Mass Spectrometry: Two Years of National Experience.

Newborn screening (NBS) for inborn errors of metabolism is one of the most advanced tools for secondary prevention in medicine, as it allows early diagnosis and prompt treatment initiation. The expanded newborn screening was introduced in Italy between 2016 and 2017 (Law 167/2016; DM 13 October 2016; DPCM 12-1-2017). A total of 1,586,578 infants born in Italy were screened between January 2017 and December 2020. For this survey, we collected data from 15 Italian screening laboratories, focusing on the metabolic disorders identified by tandem mass spectrometry (MS/MS) based analysis between January 2019 and December 2020. Aminoacidemias were the most common inborn errors in Italy, and an equal percentage was observed in detecting organic acidemias and mitochondrial fatty acids beta-oxidation defects. Second-tier tests are widely used in most laboratories to reduce false positives. For example, second-tier tests for methylmalonic acid and homocysteine considerably improved the screening of CblC without increasing unnecessary recalls. Finally, the newborn screening allowed us to identify conditions that are mainly secondary to a maternal deficiency. We describe the goals reached since the introduction of the screening in Italy by exchanging knowledge and experiences among the laboratories.

Genotype-phenotype correlations and disease mechanisms in PEX13-related Zellweger spectrum disorders.

BACKGROUND: Pathogenic variants in PEX-genes can affect peroxisome assembly and function and cause Zellweger spectrum disorders (ZSDs), characterized by variable phenotypes in terms of disease severity, age of onset and clinical presentations. So far, defects in at least 15 PEX-genes have been implicated in Mendelian diseases, but in some of the ultra-rare ZSD subtypes genotype-phenotype correlations and disease mechanisms remain elusive. METHODS: We report five families carrying biallelic variants in PEX13. The identified variants were initially evaluated by using a combination of computational approaches. Immunofluorescence and complementation studies on patient-derived fibroblasts were performed in two patients to investigate the cellular impact of the identified mutations. RESULTS: Three out of five families carried a recurrent p.Arg294Trp non-synonymous variant. Individuals affected with PEX13-related ZSD presented heterogeneous clinical features, including hypotonia, developmental regression, hearing/vision impairment, progressive spasticity and brain leukodystrophy. Computational predictions highlighted the involvement of the Arg294 residue in PEX13 homodimerization, and the analysis of blind docking predicted that the p.Arg294Trp variant alters the formation of dimers, impairing the stability of the PEX13/PEX14 translocation module. Studies on muscle tissues and patient-derived fibroblasts revealed biochemical alterations of mitochondrial function and identified mislocalized mitochondria and a reduced number of peroxisomes with abnormal PEX13 concentration. CONCLUSIONS: This study expands the phenotypic and mutational spectrum of PEX13-related ZSDs and also highlight a variety of disease mechanisms contributing to PEX13-related clinical phenotypes, including the emerging contribution of secondary mitochondrial dysfunction to the pathophysiology of ZSDs.

Clinical, imaging, biochemical and molecular features in Leigh syndrome: a study from the Italian network of mitochondrial diseases.

BACKGROUND: Leigh syndrome (LS) is a progressive neurodegenerative disorder associated with primary or secondary dysfunction of mitochondrial oxidative phosphorylation and is the most common mitochondrial disease in childhood. Numerous reports on the biochemical and molecular profiles of LS have been published, but there are limited studies on genetically confirmed large series. We reviewed the clinical, imaging, biochemical and molecular data of 122 patients with a diagnosis of LS collected in the Italian Collaborative Network of Mitochondrial Diseases database. RESULTS: Clinical picture was characterized by early onset of several neurological signs dominated by central nervous system involvement associated with both supra- and sub-tentorial grey matter at MRI in the majority of cases. Extraneurological organ involvement is less frequent in LS than expected for a mitochondrial disorder. Complex I and IV deficiencies were the most common biochemical diagnoses, mostly associated with mutations in SURF1 or mitochondrial-DNA genes encoding complex I subunits. Our data showed SURF1 as the genotype with the most unfavorable prognosis, differently from other cohorts reported to date. CONCLUSION: We report on a large genetically defined LS cohort, adding new data on phenotype-genotype correlation, prognostic factors and possible suggestions to diagnostic workup.

Long-term clinical outcome of 6-pyruvoyl-tetrahydropterin synthase-deficient patients.

INTRODUCTION: 6-Pyruvoyl-tetrahydropterin synthase deficiency (PTPSd) is a rare autosomal recessive disorder of synthesis of biogenic amines, which is characterized by variable neurological impairment and hyperphenylalaninemia. We aimed to assess the long-term clinical outcome of this disorder and the factors affecting it. METHODS: At total of 28 PTPSd patients (aged 19.9 ±â€¯10.9 years) underwent clinical (neurological and psychiatric) and neuropsychological assessment (BRIEF, VABS-II, and IQ). Based on CSF homovanillic (HVA) and 5-hydroxyindolacetic acid (5-HIAA) and pterin concentrations at diagnosis, patients were classified as having either a severe [SF; low level of CSF, HVA, and 5-HIAA with altered neopterin/biopterin (Neo/Bio)] or mild form (MF; normal HVA and 5-HIAA with altered Neo/Bio) of PTPSd. RESULTS: Approximately 36% of patients had MF PTPSd. At the last examination, 43% of patients had movement disorders (2 MF, 10 SF), 43% of patients had variable degrees of intellectual disability (SF only), 39% met the criteria for a psychiatric disorder (3 MF, 9 SF). Applying a linear regression model, we found that HVA and phenylalanine levels at birth had a significant influence on IQ, BRIEF, and VABS-II variability. Lastly, 5-HIAA further contributed to VABS-II variability. The disease showed a self-limiting clinical course and its treatment, although delayed, is effective in improving the neurological status. CONCLUSIONS: Neurodevelopmental impairment due to PTPSd shows a self-limiting course. A continuous improvement in the neurological condition has been observed in patients receiving treatment, even when delayed. The severity of brain biogenic amine depletion at diagnosis predicts neurological and psychiatric outcomes.

Combined early treatment in hemiplegic attacks related to CACNA1A encephalopathy with brain oedema: Blocking the cascade?

Introduction Variants in the CACNA1A gene on chromosome 19p13 result in a spectrum of neurological phenotypes ranging from familial or sporadic hemiplegic migraine to congenital or progressive encephalopathies. Patients with CACNA1A variants often show acute attacks with ataxia or hemiplegia till coma, sometimes related to unilateral brain oedema. No guidelines for the medical management of these attacks are available since treatment is empiric, and many cases do not respond to common antimigraine drugs. Case description We report on the emergency personalized treatment protocol used in an 11 year-old girl with CACNA1A-related encephalopathy for the management of acute attacks of headache, hemiconvulsions and hemiplegia with coma. Discussion Combined corticosteroid pulses and hypertonic solution led to a reduction in severity and duration of acute attacks when administered in the early stages, characterized by migraine, seizure, fever, vomiting and impairment of consciousness associated to hemispheric slowing on the EEG.

Long-term outcome and need of re-operation in gastro-esophageal reflux surgery in children.

BACKGROUND: Fundoplication is considered a mainstay in the treatment of gastro-esophageal reflux. However, the literature reports significant recurrences and limited data on long-term outcome. AIMS: To evaluate our long-term outcomes of antireflux surgery in children and to assess the results of redo surgery. METHODS: We retrospectively analyzed all patients who underwent Nissen fundoplication in 8 consecutive years. Reiterative surgery was indicated only in case of symptoms and anatomical alterations. A follow-up study was carried out to analyzed outcome and patients' Visick score assessed parents' perspective. RESULTS: Overall 162 children were included for 179 procedures in total. Median age at first intervention was 43 months. Comorbidities were 119 (73 %), particularly neurological impairments (73 %). Redo surgery is equal to 14 % (25/179). Comorbidities were risk factors to Nissen failure (p = 0.04), especially children suffering neurological impairment with seizures (p = 0.034). Follow-up datasets were obtained for 111/162 = 69 % (median time: 51 months). Parents' perspectives were excellent or good in 85 %. CONCLUSIONS: A significant positive impact of redo Nissen intervention on the patient's outcome was highlighted; antireflux surgery is useful and advantageous in children and their caregivers. Children with neurological impairment affected by seizures represent significant risk factors.

New insights into central nervous system involvement in FOP: Case report and review of the literature.

Fibrodyspasia ossificans progressiva is an autosomal dominant disease due to activating mutations in activin receptor type IA and characterized by progressive heterotopic ossification. Recently, the same non-synonymous heterozygous somatic mutations of ACVR1 have been identified in brain biopsies or autopsy of 24-27% of patients with a rare cerebral tumor, the diffuse intrinsic pontine glioma. We report the first case of a patient with FOP with incidental findings of an abnormal soft tissue mass surrounding the brainstem and causing obstructive hydrocephalus, associated with bilateral dentate lesions. Clinico-radiological course during 10 years of follow-up was consistent with a benign lesion, excluding an oncogenic role of ACVR1 mutations.

Short-term survival of hyperammonemic neonates treated with dialysis.

BACKGROUND: In severe neonatal hyperammonemia, extracorporeal dialysis (ECD) provides higher ammonium clearance than peritoneal dialysis (PD). However, there are limited outcome data in relation to dialysis modality. METHODS: Data from infants with hyperammonemia secondary to inborn errors of metabolism (IEM) treated with dialysis were collected in six Italian centers and retrospectively analyzed. RESULTS: Forty-five neonates born between 1990 and 2011 were enrolled in the study. Of these, 23 were treated with PD and 22 with ECD (14 with continuous venovenous hemodialysis [CVVHD], 5 with continuous arteriovenous hemodialysis [CAVHD], 3 with hemodialysis [HD]). Patients treated with PD experienced a shorter duration of predialysis coma, while those treated with HD had a shorter ammonium decay time compared with all the other patients (p < 0.05). No difference in ammonium reduction rate was observed between patients treated with PD, CAVHD or CVVHD. Carbamoyl phosphate synthetase deficiency (CPS) was significantly associated with increased risk of death (OR: 9.37 [1.52-57.6], p = 0.016). Predialysis ammonium levels were significantly associated with a composite end-point of death or neurological sequelae (adjusted OR: 1.13 [1.02-1.27] per 100 µmol/l, p = 0.026). No association was found between outcome and dialysis modality. CONCLUSIONS: In this study, a delayed ECD treatment was not superior to PD in improving the short-term outcome of neonates with hyperammonemia secondary to IEM.

Interstitial 7q31.1 copy number variations disrupting IMMP2L gene are associated with a wide spectrum of neurodevelopmental disorders.

BACKGROUND: Since the introduction of the array-CGH technique in the diagnostic workup of mental retardation, new recurrent copy number variations and novel microdeletion/microduplication syndromes were identified. These findings suggest that some genomic disorders have high penetrance but a wide range of phenotypic severity. RESULTS: We present the clinical and molecular description of four unrelated patients affected by neurodevelopmental disorders and overlapping 7q31.1 microdeletion/microduplication, identified by array-CGH and involving only part of the IMMP2L gene. CONCLUSION: IMMP2L encodes an inner mitochondrial membrane protease-like protein, which is required for processing of cytochromes inside mitochondria. Numerous studies reported that this gene is implicated in behavioural disorders such as autistic spectrum disorders, attention-deficit hyperactivity disorders, and Gilles de la Tourette syndrome. We discuss the functions of the gene suggesting that IMMP2L may act as risk factor for neurological disease.

SMAD4 mutations causing Myhre syndrome result in disorganization of extracellular matrix improved by losartan.

Myhre syndrome (MS, MIM 139210) is a connective tissue disorder that presents with short stature, short hands and feet, facial dysmorphic features, muscle hypertrophy, thickened skin, and deafness. Recurrent missense mutations in SMAD4 encoding for a transducer mediating transforming growth factor ß (TGF-ß) signaling are responsible for MS. We found that MS fibroblasts showed increased SMAD4 protein levels, impaired matrix deposition, and altered expression of genes encoding matrix metalloproteinases and related inhibitors. Increased TGF-ß signaling and progression of aortic root dilation in Marfan syndrome can be prevented by the antihypertensive drug losartan, a TGF-ß antagonists and angiotensin-II type 1 receptor blocker. Herein, we showed that losartan normalizes metalloproteinase and related inhibitor transcript levels and corrects the extracellular matrix deposition defect in fibroblasts from MS patients. The results of this study may pave the way toward therapeutic applications of losartan in MS.

A new SPINK5 mutation in a patient with Netherton syndrome: a case report.

We report on a case of Netherton syndrome showing a new SPINK5 mutation (c.957_960dupTGGT duplication in exon 11), associated with partial defect of biotinidase.

Laparoscopic proximal Roux-en-Y gastrojejunal diversion in children: preliminary experience from a single center.

BACKGROUND: Neurologically impaired children (NIC) have a high risk of recurrence of gastroesophageal reflux (GER) following fundoplication. A postpyloric feeding tube may be useful when gastric emptying disorders occur; however, dislocation and difficulty in feeding management often require more aggressive procedures. Total esophagogastric dissociation (Bianchi's TEGD) is an alternative to the classic fundoplication procedure, whereas laparoscopic gastric bypass is a frequently performed procedure in morbid obesity, improving gastric outlet. AIM: The aim of this paper is to present a preliminary experience on the laparoscopic Roux-en-Y gastrojejunal bypass, associated with Nissen fundoplication and gastrostomy, to treat and prevent GER in NIC with gastric emptying disorders. MATERIALS AND METHODS: Eight neurologically impaired children underwent surgical treatment because of feeding problems and pulmonary complications. The procedure included: 1) hiatoplasty, 2) Nissen fundoplication, 3) 20-cm Roux-en-Y gastrojejunal anastomosis and jejuno-jejunal anastomosis, and 4) gastrostomy. RESULTS: All cases were fed on postoperative day 3 without any intraoperative complications. One case developed an obstruction of the distal anastomosis due to adhesion and needed reoperation. Outcome was clinically evaluated with serial upper gastrointestinal contrast studies and endoscopies. CONCLUSIONS: Laparoscopic proximal Roux-en-Y gastrojejunal diversion, without gastric resection, is a safe, feasible procedure that improves gastric emptying and reduces the risk of GER recurrence. Yet, long-term results still have to be evaluated.

Spectrum of MMACHC mutations in Italian and Portuguese patients with combined methylmalonic aciduria and homocystinuria, cblC type.

Methylmalonic aciduria (MMA) and homocystinuria, cblC type (MIM 277400) is the most frequent inborn error of vitamin B(12). The recent identification of the disease gene, MMACHC, has permitted preliminary genotype-phenotype correlations. We studied 24 Italian and 17 Portuguese patients with cblC defect to illustrate the spectrum of mutations in a southern European population and discuss the impact that mutation identification has on routine diagnostic procedures. Since the metabolic defect raises the serum levels of homocysteine, we also tested if variants in MTHFR-playing a key role in homocysteine remethylation pathway-could act as genetic modifier in cblC defect. We found that the c.271dupA (accounting for 55% of the MMACH alleles in our cohort) followed by c.394C>T (16%) and c.331C>T (9%) were the most frequent mutations. In our study we also identified a novel mutation (c.544T>C). On the other hand, the MTHFR genotype did not appear to influence age at onset, the clinical phenotype and outcome of patients with cblC defect. This study shows that mutation screening for the most common MMACH mutations occurring in early-onset forms (c.271dupA and c.331C>T) seems to have a high diagnostic yield in a southern European population with cblC defect. Although the identification of the gene defect per se does not predict completely time and severity of disease appearance, our data corroborate the importance of a molecular testing to offer accurate prenatal diagnosis to couples at high risk of having affected children.

Severe epilepsy in X-linked creatine transporter defect (CRTR-D).

Disorders of creatine synthesis or its transporter resulting in neurological impairment with mental retardation and epilepsy have only been recognized in recent years. To date, the epileptic disorder observed in creatine transporter deficiency (CRTR-D) has been described as a mild phenotype with infrequent seizures and favorable response to common antiepileptic drugs. We report on a 5 year-old boy with known speech delay who presented with severe and refractory epilepsy. After extensive investigations, metabolite analysis and brain 1H-MRS suggested CRTR-D, which was confirmed by the detection of a known pathogenic mutation in the SLC6A8 gene (c.1631C>T; p.Pro544Leu).

Severe lactic acidosis due to thiamine deficiency in a patient with B-cell leukemia/lymphoma on total parenteral nutrition during high-dose methotrexate therapy.

An 11-month-old girl with B-cell leukemia/lymphoma developed profound lethargy due to severe lactic acidosis during chemotherapy and total parenteral nutrition (TPN). Initial treatment with NaHCO3 was ineffective. Treatment with a vitamin cocktail (OH-cobalamin, pyridoxine, thiamine, riboflavine, biotin, carnitine) at pharmacologic doses rapidly improved the child's clinical and laboratory status. Lactic acidosis was caused by an impairment of pyruvate dehydrogenase complex, which was due to lack of its necessary cofactor thiamine in the TPN. This case report indicates that lactic acidosis may be a front-line diagnosis in patients on TPN with lethargy and outlines the need for monitoring thiamine supply in TPN.

Early-onset cobalamin C/D deficiency: epilepsy and electroencephalographic features.

PURPOSE: To describe epilepsy and EEG findings in the early-onset cobalamin (Cbl) C/D deficiency, an inborn error of intracellular Cbl metabolism characterized by high plasma levels of methylmalonic acid, homocystine, and homocysteine. METHODS: Type and frequency of seizures were studied in 10 patients (six boys and four girls) who underwent waking and sleep EEG. RESULTS: Half of patients had seizures in the first year of life (either concurrent with the other symptoms of disease or some months after the onset of disease); seizures occurred after 2 years in the other half of patients. Convulsive status epilepticus was the initial manifestation in three patients. During the follow-up, nine patients had seizures (mainly partial) despite specific treatment for Cbl C/D deficiency and antiepileptic drugs. Focal or multifocal epileptiform abnormalities during waking EEG that increased during sleep EEG were recorded in the majority of patients. Plasma levels of homocystine and homocysteine were constantly higher than normal, despite therapy institution. CONCLUSIONS: Epilepsy and EEG abnormalities are prominent features in the early-onset type of combined methylmalonic aciduria and homocystinuria due to Cbl C/D deficiency, possibly related to the pathologically and persistently high levels of homocysteine, experimentally proven to induce seizures. Plasma amino acids evaluation and urinary acid organic analysis should be performed in any infant showing seizures associated with feeding difficulties and failure to thrive, at onset during the first year of life, as well as in any child with convulsive status epilepticus and a history of psychomotor developmental delay of unknown origin.