Establishing Patient-Centered Outcomes for MCT8 Deficiency: Stakeholder Engagement and Systematic Literature Review.

Introduction: The gene encodes the thyroid hormone (TH) transporter MCT8. Pathogenic variants result in a reduced TH uptake into the CNS despite high serum T3 concentrations. Patients suffer from severe neurodevelopmental delay and require multidisciplinary care.

Understanding caregiver descriptions of initial signs and symptoms to improve diagnosis of metachromatic leukodystrophy.

Background: Metachromatic leukodystrophy (MLD), a relentlessly progressive and ultimately fatal condition, is a rare autosomal recessive lysosomal storage disorder caused by a deficiency of the enzyme arylsulfatase A (ARSA). Historically management has been palliative or supportive care. Hematopoietic stem cell transplantation is poorly effective in early-onset MLD and benefit in late-onset MLD remains controversial.

An international study of caregiver-reported burden and quality of life in metachromatic leukodystrophy.

Background: Metachromatic leukodystrophy (MLD) is an autosomal recessive lysosomal disorder caused by mutations in the arylsulfatase A gene. Until now, there has been little information on the burden of MLD on patients and their caregivers. This multinational study aims to quantify caregiver-related impacts of MLD across several key domains including symptoms, treatment burden, time investment, social and emotional well-being, and professional and financial impact.

Expanding the phenotypic spectrum of Allan-Herndon-Dudley syndrome in patients with SLC16A2 mutations.

The aim of the study was to redefine the phenotype of Allan-Herndon-Dudley syndrome (AHDS), which is caused by mutations in the SLC16A2 gene that encodes the brain transporter of thyroid hormones. Clinical phenotypes, brain imaging, thyroid hormone profiles, and genetic data were compared to the existing literature. Twenty-four males aged 11 months to 29 years had a mutation in SLC16A2, including 12 novel mutations and five previously described mutations.

Leukodystrophies and genetic leukoencephalopathies in children.

Leukodystrophies and genetic leukoencephalopathies are a large group of genetic disorders affecting central nervous system white matter. They can begin at any age, however this study focuses on disorders beginning in childhood and adolescence. We discuss the recent definitions, classifications, and classic syndromes, as well as genetic progress in the field through the identification of new genes and several new genetic syndromes.

Brain Diffusion Imaging and Tractography to Distinguish Clinical Severity of Human PLP1-Related Disorders.

Aims: We performed quantitative diffusion tensor imaging and brain tractography to distinguish clinical severity in a series of 35 patients with hypomyelinating PLP1-related disorders classified using the Motor Developmental Score according to the best motor function acquired before the age of 5 years and the gross motor function measure (GMFM) at the time of magnetic resonance imaging acquisition.

Methods: We calculated fractional anisotropy and diffusivity values in 26 regions of interest and the numbers of fibers and volumes of hemisphere tractograms. Fiber bundles on tractograms were characterized according to 3 criteria: size, direction of main-stream fibers, and connectivity of bundles (extratelencephalic projections, commissural fibers, and intrahemispheric connections).

IQSEC2-related encephalopathy in males and females: a comparative study including 37 novel patients.

Purpose: Variants in IQSEC2, escaping X inactivation, cause X-linked intellectual disability with frequent epilepsy in males and females. We aimed to investigate sex-specific differences.

Methods: We collected the data of 37 unpublished patients (18 males and 19 females) with IQSEC2 pathogenic variants and 5 individuals with variants of unknown significance and reviewed published variants.