Case Report
ANovelMutationinthe EIF2B4 GeneAssociatedwith
LeukoencephalopathywithVanishingWhiteMatter
D.Hettiaracchchi ,
1
N.Neththikumara,
1
B.A.P.S.Pathirana,
1
A.Padeniya,
2
andV.H.W.Dissanayake
1
1
Human Genetics Unit, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka
2
National Hospital of Sri Lanka, Colombo, Sri Lanka
Correspondence should be addressed to D. Hettiaracchchi; dinebine@gmail.com
Received 21 March 2018; Accepted 6 June 2018; Published 5 July 2018
Academic Editor: Ozgur Cogulu
Copyright © 2018 D. Hettiaracchchi et al. is is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
1.Introduction
Leukoencephalopathy with vanishing white matter (VWM;
MIM #603896) is an autosomal recessive disorder, charac-
terized by childhood ataxia, spasticity, and variable optic at-
rophy. e course is chronic progressive with episodes of rapid
deterioration, provoked by febrile illnesses, minor head
trauma, or acute fright, with most patients succumbing to
illness within few years of onset. ree forms of VWM has been
described based on disease onset, which ranges from a subacute
infantile form (onset age <1 year), an early childhood form
(onset age 1–5 years), and a late-childhood/juvenile form
(onset age 5–15 years) [1–3]. e diagnosis is based on clinical
findings, characteristic MRI features indicative of vanishing of
the cerebral white matter, and an identifiable pathogenic
variant in one of the genes (EIF2B1, EIF2B2, EIF2B3, EIF2B4,
and EIF2B5) encoding for the 5 subunits of eukaryotic
translation initiation factor 2B (eIF2B), which is essential in all
cells of the body for the initiation of translation of RNA into
protein during protein synthesis and its regulation under
different stress conditions such as fever [4, 5]. Its effect is
predominantly seen on oligodendrocytes and astrocytes while
there is sparing of other cell types [2].
2.CaseReport
e proband is the only child of a 2nd degree consan-
guineous marriage of Sri Lankan origin. She was well up to 8
months when she developed a fever for one day, following
which the child had acute developmental regression that
lasted for 3 months accompanied with bilateral lower limb
weakness and speech regression. e child then developed
an upper respiratory tract infection, following which she was
unresponsive for 30 minutes. e MRI scan showed marked
hyperintense and subcortical white matter in T2 WI bi-
laterally with involvement of dentate nuclei and white
matter tracts. Myelination was around 3 months, which
corresponded to the current developmental age of the child.
All biochemical parameters were within normal limits. e
proband succumbed to illness at 18 months. She also had
a first cousin with similar features who died at the age of 21
years (Figure 1).
3.Methods
3.1.WholeExomeSequencing. DNA was extracted from the
proband’s whole blood leucocytes using Qiagen DNA ex-
traction Mini KITaccording to the manufacturer’s protocol.
Whole exome sequencing (WES) of the extracted DNA was
performed on an Illumina
®
HiSeq 4000 Next Generation
Sequencer using the SureSelect
®
Human All Exon V6 kit.
3.2. Bioinformatics Analysis. Data analysis was performed
using an in-house-developed variant calling annotation
pipeline. Paired-end Fastq files were aligned to the GrCh37
human reference sequence using BWA-MEM algorithm to
produce SAM file. e SAM to BAM conversion, sorting, and
Hindawi
Case Reports in Pediatrics
Volume 2018, Article ID 2731039, 4 pages
https://doi.org/10.1155/2018/2731039