Cerebral hypomyelination associated with biallelic variants of FIG4

The lipid phosphatase gene FIG4 is responsible for Yunisâ Varón syndrome and Charcotâ Marieâ Tooth disease Type 4J, a peripheral neuropathy. We now describe four families with FIG4 variants and prominent abnormalities of central nervous system (CNS) white matter (leukoencephalopathy), with onset in early childhood, ranging from severe hypomyelination to mild undermyelination, in addition to peripheral neuropathy. Affected individuals inherited biallelic FIG4 variants from heterozygous parents. Cultured fibroblasts exhibit enlarged vacuoles characteristic of FIG4 dysfunction. Two unrelated families segregate the same Gâ >â A variant in the +1 position of intron 21 in the homozygous state in one family and compound heterozygous in the other. This mutation in the splice donor site of exon 21 results in readâ through from exon 20 into intron 20 and truncation of the final 115 Câ terminal amino acids of FIG4, with retention of partial function. The observed CNS white matter disorder in these families is consistent with the myelination defects in the FIG4 null mouse and the known role of FIG4 in oligodendrocyte maturation. The families described here the expanded clinical spectrum of FIG4 deficiency to include leukoencephalopathy.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149294/1/humu23720-sup-0001-Supp_Mat_Lenk_2018.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149294/2/humu23720.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149294/3/humu23720_am.pd

Genetic and phenotypic spectrum associated with IFIH1 gain-of-function

IFIH1 gain-of-function has been reported as a cause of a type I interferonopathy encompassing a spectrum of autoinflammatory phenotypes including Aicardi–Goutières syndrome and Singleton Merten syndrome. Ascertaining patients through a European and North American collaboration, we set out to describe the molecular, clinical and interferon status of a cohort of individuals with pathogenic heterozygous mutations in IFIH1. We identified 74 individuals from 51 families segregating a total of 27 likely pathogenic mutations in IFIH1. Ten adult individuals, 13.5% of all mutation carriers, were clinically asymptomatic (with seven of these aged over 50 years). All mutations were associated with enhanced type I interferon signaling, including six variants (22%) which were predicted as benign according to multiple in silico pathogenicity programs. The identified mutations cluster close to the ATP binding region of the protein. These data confirm variable expression and nonpenetrance as important characteristics of the IFIH1 genotype, a consistent association with enhanced type I interferon signaling, and a common mutational mechanism involving increased RNA binding affinity or decreased efficiency of ATP hydrolysis and filament disassembly rate

Ethnic representation in interventional clinical trials run in India

Summary: Globally, the need to enhance the diversity of trial participants is receiving increasingly urgent attention. We wanted to know whether trials run in India had adequately sampled the country's enormous ethnic diversity. We accessed the Clinical Trials Registry-India website to determine whether each interventional drug or biologic Phase 2 or 3 study, registered in a recent five-year period had run in each of six geographic zones. As regards Phase 3 trials conducted only in India, 61.4% ran in a single zone and just 6.8% were conducted in all six zones. Multinational Phase 3 trials had a better distribution since 3.6% had run in just one zone and 7.1% in all six. India's diverse ethnic groups are underrepresented in the majority of trials covered in this study. A trial that is conducted on non-representative groups and later discovered to be harmful or ineffective in parts of the population, is unethical. We propose various remedial steps

Genetic and phenotypic spectrum associated with IFIH1 gain-of-function

IFIH1 gain-of-function has been reported as a cause of a type I interferonopathy encompassing a spectrum of autoinflammatory phenotypes including Aicardi-Goutières syndrome and Singleton Merten syndrome. Ascertaining patients through a European and North American collaboration, we set out to describe the molecular, clinical and interferon status of a cohort of individuals with pathogenic heterozygous mutations in IFIH1. We identified 74 individuals from 51 families segregating a total of 27 likely pathogenic mutations in IFIH1. Ten adult individuals, 13.5% of all mutation carriers, were clinically asymptomatic (with seven of these aged over 50 years). All mutations were associated with enhanced type I interferon signaling, including six variants (22%) which were predicted as benign according to multiple in silico pathogenicity programs. The identified mutations cluster close to the ATP binding region of the protein. These data confirm variable expression and nonpenetrance as important characteristics of the IFIH1 genotype, a consistent association with enhanced type I interferon signaling, and a common mutational mechanism involving increased RNA binding affinity or decreased efficiency of ATP hydrolysis and filament disassembly rate