Phenylketonuria (PKU) is an autosomal recessive inborn error of phenylalanine metabolism caused by deficiency in the enzyme phenylalanine hydroxylase that converts phenylalanine into tyrosine. If ...left untreated, PKU results in increased phenylalanine concentrations in blood and brain, which cause severe intellectual disability, epilepsy and behavioural problems. PKU management differs widely across Europe and therefore these guidelines have been developed aiming to optimize and standardize PKU care. Professionals from 10 different European countries developed the guidelines according to the AGREE (Appraisal of Guidelines for Research and Evaluation) method. Literature search, critical appraisal and evidence grading were conducted according to the SIGN (Scottish Intercollegiate Guidelines Network) method. The Delphi-method was used when there was no or little evidence available. External consultants reviewed the guidelines. Using these methods 70 statements were formulated based on the highest quality evidence available. The level of evidence of most recommendations is C or D. Although study designs and patient numbers are sub-optimal, many statements are convincing, important and relevant. In addition, knowledge gaps are identified which require further research in order to direct better care for the future.
Background and purpose
Guidelines on monogenic cerebral small‐vessel disease (cSVD) diagnosis and management are lacking. Endorsed by the Stroke and Neurogenetics Panels of the European Academy of ...Neurology, a group of experts has provided recommendations on selected monogenic cSVDs, i.e. cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL), autosomal dominant High Temperature Requirement A Serine Peptidase 1 (HTRA1), cathepsin‐A‐related arteriopathy with strokes and leukoencephalopathy (CARASAL), pontine autosomal dominant microangiopathy and leukoencephalopathy (PADMAL), Fabry disease, mitochondrial encephalopathy, lactic acidosis and stroke‐like episodes (MELAS) and type IV collagen (COL4)A1/2.
Methods
We followed the Delphi methodology to provide recommendations on several unanswered questions related to monogenic cSVD, including genetic testing, clinical and neuroradiological diagnosis, and management.
Results
We have proposed ‘red‐flag’ features suggestive of a monogenic disease. General principles applying to the management of all cSVDs and specific recommendations for the individual forms of monogenic cSVD were agreed by consensus.
Conclusions
The results provide a framework for clinicians involved in the diagnosis and management of monogenic cSVD. Further multicentre observational and treatment studies are still needed to increase the level of evidence supporting our recommendations.
Three young patients with glutaric aciduria type I (age 6–23 years) of different ethnic origins, treated for their metabolic disease since early childhood, presented with malignant central nervous ...system tumors. We recommend continuing clinical follow-up, including monitoring of neurological manifestations and neuroradiological findings, in all patients with glutaric aciduria type I beyond early childhood, especially if adherence to diet is poor or the treatment was not started neonatally.
Classical galactosemia is an autosomal recessive inborn error of metabolism due to mutations of the GALT gene leading to toxic accumulation of galactose and derived metabolites. With the benefit of ...early diagnosis by neonatal screening and early therapy, the acute presentation of classical galactosemia can be prevented. However, despite early diagnosis and treatment, the long term outcome for these patients is still unpredictable because they may go on to develop cognitive disability, speech problems, neurological and/or movement disorders and, in females, ovarian dysfunction. The objectives of the current study were to report our experience with a group of galactosemic patients identified through the neonatal screening programs in northeastern Italy during the last 30years.
No neonatal deaths due to galactosemia complications occurred after the introduction of the neonatal screening program. However, despite the early diagnosis and dietary treatment, the patients with classical galactosemia showed one or more long-term complications.
A total of 18 different variations in the GALT gene were found in the patient cohort: 12 missense, 2 frameshift, 1 nonsense, 1 deletion, 1 silent variation, and 1 intronic. Six (p.R33P, p.G83V, p.P244S, p.L267R, p.L267V, p.E271D) were new variations. The most common variation was p.Q188R (12 alleles, 31.5%), followed by p.K285N (6 alleles, 15.7%) and p.N314D (6 alleles, 15.7%). The other variations comprised 1 or 2 alleles. In the patients carrying a new mutation, the biochemical analysis of GALT activity in erythrocytes showed an activity of <1%. In silico analysis (SIFT, PolyPhen-2 and the computational analysis on the static protein structure) showed potentially damaging effects of the six new variations on the GALT protein, thus expanding the genetic spectrum of GALT variations in Italy. The study emphasizes the difficulty in establishing a genotype–phenotype correlation in classical galactosemia and underlines the importance of molecular diagnostic testing prior to making any treatment.
Three-dimensional model of the dimeric GALT enzyme. The two chains A and B forming the dimer are colored in green and cyan, respectively. Secondary structures of the enzyme are represented as springs (for helices) and ribbons (for strands). The residues for each monomer affected by the six novel mutations described in this article (p.R33P, p.G83V, p.P244S, p.L267R, p.L267V, E271D) are shown in CPK mode and labeled. Display omitted
•Mutational spectrum of galactosemic patients from Northeast Italy was investigated.•A total of 18 different variations on GALT gene were found in the patients.•Six new missense variations were identified in the patients.•In silico analysis showed a potentially damaging effect of the new variations.•Biochemical analysis showed GALT activity <1% in patients with new variations.
Phenylketonuria (PKU) is an autosomal recessive inborn error of phenylalanine metabolism caused by deficiency in the enzyme phenylalanine hydroxylase that converts phenylalanine into tyrosine.
In ...2017 the first European PKU Guidelines were published. These guidelines contained evidence based and/or expert opinion recommendations regarding diagnosis, treatment and care for patients with PKU of all ages. This manuscript is a supplement containing the practical application of the dietary treatment.
This handbook can support dietitians, nutritionists and physicians in starting, adjusting and maintaining dietary treatment.
Fabry disease is an X-linked lysosomal deficiency of α-galactosidase A that results in cellular accumulation of galactoconjugates, mainly globotriaosylceramide, particularly in blood vessels. ...Neuroradiological findings include ischemic stroke, white matter lesions, vascular abnormalities (vertebrobasilar dolichoectasia and vessel tortuosity), and posterior thalamus involvement (the so called
pulvinar sign
). The purpose of our study was to investigate the presence of the increased pulvinar signal intensity on T1-weighted imaging –
pulvinar sign
and its relationship with other clinical findings, in a non-selected cohort of Fabry patients.
Methods
We performed a prospective analysis of two populations of patients (36 subjects) with Fabry disease. Patients were followed-up at the Department of Internal Medicine of the Bichat Hospital in Paris (France) and at the Neurological Clinic of the University Hospital of Padova (Italy). Brain MR studies of each patient included T1- and T2- weighted images, FLAIR sequences, and in some cases diffusion weighted images.
Results
A total of 36 patients (16 males, 20 females) were investigated in 14 families. The
pulvinar sign
was found in 5 male patients, but not in female patients. Seven patients had had at least one stroke (territorial or lacunar). There was no correlation between stroke and the pulvinar sign. All patients with the
pulvinar sign
had hypertrophic cardiomyopathy. Four patients out of five with the
pulvinar sign
were on dialysis or had a kidney transplantation.
Conclusions
Our findings suggest that the
pulvinar sign
is a highly specific sign of Fabry disease, found in male patients with cardiac signs and severe kidney involvement.
Summary
Glutaryl‐CoA dehydrogenase (GCDH) deficiency is an autosomal recessive disease with an estimated overall prevalence of 1 in 100 000 newborns. Biochemically, the disease is characterized by ...accumulation of glutaric acid, 3‐hydroxyglutaric acid, glutaconic acid, and glutarylcarnitine, which can be detected by gas chromatography–mass spectrometry of organic acids or tandem mass spectrometry of acylcarnitines. Clinically, the disease course is usually determined by acute encephalopathic crises precipitated by infectious diseases, immunizations, and surgery during infancy or childhood. The characteristic neurological sequel is acute striatal injury and, subsequently, dystonia. During the last three decades attempts have been made to establish and optimize therapy for GCDH deficiency. Maintenance treatment consisting of a diet combined with oral supplementation of L‐carnitine, and an intensified emergency treatment during acute episodes of intercurrent illness have been applied to the majority of patients. This treatment strategy has significantly reduced the frequency of acute encephalopathic crises in early‐diagnosed patients. Therefore, GCDH deficiency is now considered to be a treatable condition. However, significant differences exist in the diagnostic procedure and management of affected patients so that there is a wide variation of the outcome, in particular of pre‐symptomatically diagnosed patients. At this time of rapid expansion of neonatal screening for GCDH deficiency, the major aim of this guideline is to re‐assess the common practice and to formulate recommendations for diagnosis and management of GCDH deficiency based on the best available evidence.
Galactosemia type 1 is an autosomal recessive disorder of galactose metabolism, determined by a deficiency in the enzyme galactose‐1‐phosphate uridyltransferase (GALT). GALT deficiency is classified ...as severe or variant depending on biochemical phenotype, genotype and potential to develop acute and long‐term complications. Neonatal symptoms usually resolve after galactose‐restricted diet; however, some patients, despite the diet, can develop long‐term complications, in particular when the GALT enzyme activity results absent or severely decreased. The mechanisms of acute and long‐term complications are still discussed and several hypotheses are presented in the literature like enzymatic inhibition, osmotic stress, endoplasmic reticulum stress, oxidative stress, defects of glycosylation or epigenetic modification. This review summarizes the current knowledge of galactosemia, in particular the putative mechanisms of neonatal and long‐term complications and the molecular genetics of GALT deficiency.
To describe the current treatment; clinical, biochemical, and molecular findings; and clinical follow-up of patients with aromatic l-amino acid decarboxylase (AADC) deficiency.
Clinical and ...biochemical data of 78 patients with AADC deficiency were tabulated in a database of pediatric neurotransmitter disorders (JAKE). A total of 46 patients have been previously reported; 32 patients are described for the first time.
In 96% of AADC-deficient patients, symptoms (hypotonia 95%, oculogyric crises 86%, and developmental retardation 63%) became clinically evident during infancy or childhood. Laboratory diagnosis is based on typical CSF markers (low homovanillic acid, 5-hydroxyindoleacidic acid, and 3-methoxy-4-hydroxyphenolglycole, and elevated 3-O-methyl-l-dopa, l-dopa, and 5-hydroxytryptophan), absent plasma AADC activity, or elevated urinary vanillactic acid. A total of 24 mutations in the DDC gene were detected in 49 patients (8 reported for the first time: p.L38P, p.Y79C, p.A110Q, p.G123R, p.I42fs, c.876G>A, p.R412W, p.I433fs) with IVS6+ 4A>T being the most common one (allele frequency 45%).
Based on clinical symptoms, CSF neurotransmitters profile is highly indicative for the diagnosis of aromatic l-amino acid decarboxylase deficiency. Treatment options are limited, in many cases not beneficial, and prognosis is uncertain. Only 15 patients with a relatively mild form clearly improved on a combined therapy with pyridoxine (B6)/pyridoxal phosphate, dopamine agonists, and monoamine oxidase B inhibitors.
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