Severe cystic degeneration and intractable seizures in a newborn with molybdenum cofactor deficiency type B

Consensus guidelines for the diagnosis and management of isolated sulfite oxidase deficiency and molybdenum cofactor deficiencies

Sulfite intoxication is the hallmark of four ultrarare disorders that are caused by impaired sulfite oxidase activity due to genetic defects in the synthesis of the molybdenum cofactor or of the apoenzyme sulfite oxidase. Delays on the diagnosis of these disorders are common and have been caused by their unspecific presentation of acute neonatal encephalopathy with high early mortality, followed by the evolution of dystonic cerebral palsy and also by the lack of easily available and reliable diagnostic tests. There is significant variation in survival and in the quality of symptomatic management of affected children. One of the four disorders, molybdenum cofactor deficiency type A (MoCD-A) has recently become amenable to causal treatment with synthetic cPMP (fosdenopterin). The evidence base for the rational use of cPMP is very limited. This prompted the formulation of these clinical guidelines to facilitate diagnosis and support the management of patients. The guidelines were developed by experts in diagnosis and treatment of sulfite intoxication disorders. It reflects expert consensus opinion and evidence from a systematic literature search.

Congenital Brain Malformations: An Integrated Diagnostic Approach

Congenital brain malformations are abnormalities present at birth that can result from developmental disruptions at various embryonic or fetal stages. The clinical presentation is nonspecific and can include developmental delay, hypotonia, and/or epilepsy. An informed combination of imaging and genetic testing enables early and accurate diagnosis and management planning. In this article, we provide a streamlined approach to radiologic phenotyping and genetic evaluation of brain malformations. We will review the clinical workflow for brain imaging and genetic testing with up-to-date ontologies and literature references. The organization of this article introduces a streamlined approach for imaging-based etiologic classification into malformative, destructive, and migrational abnormalities. Specific radiologic ontologies are then discussed in detail, with correlation of key neuroimaging features to embryology and molecular pathogenesis.

Molybdenum cofactor deficiency: A natural history

Molybdenum cofactor deficiency (MoCD) includes three ultrarare autosomal recessive inborn errors of metabolism (MoCD type A [MoCD-A], MoCD-B, and MoCD-C) that cause sulfite intoxication disorders. This natural history study analyzed retrospective data for 58 living or deceased patients (MoCD-A, n = 41; MoCD-B, n = 17). MoCD genotype, survival, neuroimaging, and medical history were assessed retrospectively. Prospective biomarker data were collected for 21 living MoCD patients. The primary endpoint was survival to 1 year of age in MoCD-A patients. Of the 58 MoCD patients, 49 (MoCD-A, n = 36; MoCD-B, n = 13) had first presenting symptoms by Day 28 (neonatal onset; median: 2 and 4 days, respectively). One-year survival rates were 77.4% (overall), 71.8% (neonatal onset MoCD-A), and 76.9% (neonatal onset MoCD-B); median ages at death were 2.4, 2.4, and 2.2 years, respectively. The most common presenting symptoms in the overall population were seizures (60.3%) and feeding difficulties (53.4%). Sequelae included profound developmental delay, truncal hypotonia, limb hypertonia that evolved to spastic quadriplegia or diplegia, dysmorphic features, and acquired microcephaly. In MoCD-A and MoCD-B, plasma and urinary xanthine and S-sulfocysteine concentrations were high; urate remained below the normal reference range. MOCS1 mutation homozygosity was common. Six novel mutations were identified. MoCD is a severe neurodegenerative disorder that often manifests during the neonatal period with intractable seizures and feeding difficulties, with rapidly progressive significant neurologic disabilities and high 1-year mortality rates. Delineation of MoCD natural history supports evaluations of emerging replacement therapy with cPMP for MoCD-A, which may modify disease course for affected individuals.

Neonatal Seizures Revisited

Seizures are the most common neurological disorder in newborns and are most prevalent in the neonatal period. They are mostly caused by severe disorders of the central nervous system (CNS). However, they can also be a sign of the immaturity of the infant’s brain, which is characterized by the presence of specific factors that increase excitation and reduce inhibition. The most common disorders which result in acute brain damage and can manifest as seizures in neonates include hypoxic-ischemic encephalopathy (HIE), ischemic stroke, intracranial hemorrhage, infections of the CNS as well as electrolyte and biochemical disturbances. The therapeutic management of neonates and the prognosis are different depending on the etiology of the disorders that cause seizures which can lead to death or disability. Therefore, establishing a prompt diagnosis and implementing appropriate treatment are significant, as they can limit adverse long-term effects and improve outcomes. In this review paper, we present the latest reports on the etiology, pathomechanism, clinical symptoms and guidelines for the management of neonates with acute symptomatic seizures.

Dysmorphic features in a newborn with neurological, liver and kidney involvement by defective peroxisomal biogenesis. Case report

Introduction: Inborn errors of metabolism have significant morbidity and mortality rates in the neonatal period. One of these disorders is defective peroxisomal biogenesis, which causes complex and severe clinical pictures because peroxisomes are present in all nucleated cells of mammals.Case presentation: This is the case of a newborn with dysmorphic features who had seizures at birth and presented with neurological, liver, kidney and heart involvement during her 20 days of life. Necropsy confirmed liver and kidney involvement, which, together with family history of death of a sibling and a cousin, led to suspect a peroxisomal disease that was confirmed by the biochemical alterations observed.Discussion: Dysmorphism and seizures at birth may be an expression of a metabolic disease. The findings of the physical examination and the demonstration of liver, kidney and heart involvement are consistent with the initial description of Zellweger syndrome; the biochemical alterations are conclusive.Conclusions: It is necessary to define if dysmorphism is an isolated finding or if there is involvement of other organ(s) or system(s) to establish a suitable diagnosis of peroxisome biogenesis. Inborn errors of metabolism should be included in the diagnosis of dysmorphic newborns when several organs are involved, since their identification enables genetic counseling.

New Insights into the Cystine-Sulfite Reaction

The mechanism by which cysteine-S-sulfate is formed from the reaction of sulfite with cystine in the absence of a dedicated oxidizing agent is investigated using high-resolution NMR. Changes to reactant ratio, pH, UV light exposure and temperature were evaluated to determine the most effective conditions to achieve the maximum yield of cysteine-S-sulfate without recourse to conventional oxidizing reagents. Herein evidence is provided for both nucleophilic and radical mechanisms, by which cysteine-S-sulfate can be generated with yields of up to 96%.