scholarly journals Case Report: Compound Heterozygous Variants of SLC13A3 Identified in a Chinese Patient With Acute Reversible Leukoencephalopathy and α-Ketoglutarate Accumulation

2021 ◽  
Vol 9 ◽  
Author(s):  
Qingyun Kang ◽  
Liming Yang ◽  
Hongmei Liao ◽  
Sai Yang ◽  
Haiyang Yang ◽  
...  

Background:SLC13A3 gene encodes the Na+/dicarboxylate cotransporter 3 (NaDC3), which locates on the plasma membrane and is mainly expressed in kidney, astrocytes and the choroid plexus. It imports four to six carbon dicarboxylates together with three Na+ ions into the cytosol. Nowadays, pathogenic variants of SLC13A3 gene were found to cause acute reversible leukoencephalopathy and α-ketoglutarate accumulation (ARLIAK) in patients. Here, we report two novel SLC13A3 variants c.185C>T (p.T62M) and c.331C>T (p.R111*) identified in a Chinese patient with ARLIAK.Case Presentation: The patient was a Chinese girl aged 13 years and 7 months old, who had acute, recurrent neurological deterioration during two febrile episodes. She presented with reversible leukoencephalopathy and increased urinary excretion of α-ketoglutarate. Genetic studies revealed compound heterozygous variants (c.185C>T, p.T62M, and c.331C>T, p.R111*) in SLC13A3, which had not been reported previously.Conclusions: These findings expand the variant spectrum of SLC13A3, providing the basis for the further study of this rare disease.

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Cong Zhou ◽  
Yuanyuan Xiao ◽  
Hanbing Xie ◽  
Shanling Liu ◽  
Jing Wang

Abstract Background Usher syndrome (USH) is the most common cause of inherited deaf-blindness. The current study aimed to identify pathogenic variants in a Chinese patient with hearing loss and to report the identification of a novel p.(Phe1583Leufs*10) variant in USH2A, which met the needs of prenatal diagnosis of the patient's mother. Case presentation Genomic DNA obtained from a five-year-old girl with hearing loss was analyzed via the hearing loss-targeted gene panels. We identified the compound heterozygous variants c.8559-2A>G and c.4749delT in Usher syndrome type 2A (USH2A) gene as the underlying cause of the patient; the former variation has been reported in the literature, but not the latter. The parents of the girl were heterozygous carriers. The two variants were classified as pathogenic. Based on these findings, amniotic fluid samples were used for prenatal diagnosis of the couple's fetus, which was found to carry c.4749delT but not c.8559-2A>G variation. During the follow-up period of more than 9 months after the birth of the fetus, it was confirmed that the infant was healthy. Conclusions The results of the present study identified two compound heterozygous USH2A variants in a patient with hearing loss and reported a novel USH2A variant which expands the spectrum of USH2A variants in USH.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Shihong Zhan ◽  
Fangfang Cheng ◽  
Hailong He ◽  
Shaoyan Hu ◽  
Xing Feng

Abstract Background Transcobalamin (TC) transports vitamin B12 from blood into cells. TC II deficiency is a rare autosomal recessive disorder. It is characterized by failure to thrive, diarrhoea, pallor, anaemia, pancytopenia or agammaglobulinemia. It is usually confirmed by molecular analysis of the TCN2 gene. We report a 2-month-old girl with two novel mutations, which were first reported in humans. Case presentation We present a 2-month-old Chinese girl with pancytopenia, severe combined immunodeficiency disease, and megaloblastic anaemia. Targeted next-generation sequencing (NGS) was performed, which detected compound heterozygous variants in exon 7 of the TCN2 gene (Mutation 1: c.1033 C > T; Mutation 2: c.1017-1031delinsGTAACAGAGATGGTT). These mutations result in stop codons in TCN2. The c.1033C > T mutation causes a stop at codon 345 (p.Gln345Ter), and the c.1017-1031delinsGTAACAGAGATGGTT mutation causes a stop at codon 340 (p.Leu340Ter). After being diagnosed, she was treated with intramuscular 1 mg hydroxycobalamin (OH-Cbl) every day for 2 months. The CBC value returned to normal after half a month. The peripheral blood lymphocyte subsets and immunoglobulin recovered after 2 months. Then, the dosage of OH-Cbl was gradually reduced. Conclusions TC II deficiency is a serious complication that requires lifelong treatment. Its diagnosis is difficult due to the lack of clearly identifiable symptoms. Genetic testing should be performed as early as possible if this disease is suspected. The specific observations of this case report make a considerable contribution to the literature and provide a reference for the diagnosis and treatment of future cases.


2021 ◽  
Vol 11 ◽  
Author(s):  
Jiao Liu ◽  
Xingyu Zhang ◽  
Weilan Wang ◽  
Xiaofang Lan ◽  
Minyue Dong ◽  
...  

BackgroundHarlequin ichthyosis (HI) is the most severe form of the keratinizing disorders, and it is characterized by whole-body hard stratum corneum. ABCA12 has been identified as the major disease-causing gene of HI.MethodsA case of HI was prenatally diagnosed by ultrasonography and genetic tests. The fetus had been found with dentofacial deformity and profound thickening of the palm and plantar soft tissues. Chromosomal microarray analysis (CMA) and whole exome sequencing (WES) were then performed on the amniotic fluid to identify germline pathogenic variants for the fetus. Candidate variants were verified by Sanger sequencing.ResultsCompound heterozygous frameshift variants (p.Q719QfsX21; p.F2286LfsX6) of ABCA12 were identified for the fetus, suggesting the former variants were maternally inherited and the latter paternally inherited. The fetus was terminated.ConclusionA prenatal molecular diagnosis is an important approach for the prevention of HI. In the study, we provided a successful case of genetic counseling for a family with an HI baby.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Carla De Angelis ◽  
Alicia B. Byrne ◽  
Rebecca Morrow ◽  
Jinghua Feng ◽  
Thuong Ha ◽  
...  

Abstract Background Periventricular nodular heterotopia (PNH) is a malformation of cortical development characterized by nodules of abnormally migrated neurons. The cause of posteriorly placed PNH is not well characterised and we present a case that provides insights into the cause of posterior PNH. Case presentation We report a fetus with extensive posterior PNH in association with biallelic variants in LAMC3. LAMC3 mutations have previously been shown to cause polymicrogyria and pachygyria in the occipital cortex, but not PNH. The occipital location of PNH in our case and the proposed function of LAMC3 in cortical development suggest that the identified LAMC3 variants may be causal of PNH in this fetus. Conclusion We hypothesise that this finding extends the cortical phenotype associated with LAMC3 and provides valuable insight into genetic cause of posterior PNH.


2020 ◽  
Vol 40 (6) ◽  
Author(s):  
Chunli Wei ◽  
Ting Xiao ◽  
Jingliang Cheng ◽  
Jiewen Fu ◽  
Qi Zhou ◽  
...  

Abstract As a genetically heterogeneous ocular dystrophy, gene mutations with autosomal recessive retinitis pigmentosa (arRP) in patients have not been well described. We aimed to detect the disease-causing genes and variants in a Chinese arRP family. In the present study, a large Chinese pedigree consisting of 31 members including a proband and another two patients was recruited; clinical examinations were conducted; next-generation sequencing using a gene panel was used for identifying pathogenic genes, and Sanger sequencing was performed for verification of mutations. Novel compound heterozygous variants c.G2504A (p.C835Y) and c.G6557A (p.G2186E) for the EYS gene were identified, which co-segregated with the clinical RP phenotypes. Sequencing of 100 ethnically matched normal controls didn’t found these mutations in EYS. Therefore, our study identified pathogenic variants in EYS that may cause arRP in this Chinese family. This is the first study to reveal the novel mutation in the EYS gene (c.G2504A, p.C835Y), extending its mutation spectrum. Thus, the EYS c.G2504A (p.C835Y) and c.G6557A (p.G2186E) variants may be the disease-causing missense mutations for RP in this large arRP family. These findings should be helpful for molecular diagnosis, genetic counseling and clinical management of arRP disease.


2019 ◽  
Vol 23 (3) ◽  
pp. 235-239
Author(s):  
Sakil Kulkarni ◽  
Brooj Abro ◽  
Maria Laura Duque Lasio ◽  
Janis Stoll ◽  
Dorothy K Grange ◽  
...  

We report a term female infant born to nonconsanguineous parents who presented with renal failure at birth, hypothyroidism, cholestasis, and progressive cardiac dysfunction. Multigene next-generation sequencing panels for cholestasis, cardiomyopathy, and cystic renal disease did not reveal a unifying diagnosis. Whole exome sequencing revealed compound heterozygous pathogenic variants in ANKS6 (Ankyrin Repeat and Sterile Alpha Motif Domain Containing 6), which encodes a protein that interacts with other proteins of the Inv compartment of cilium ( NEK8, NPHP2/INVS, and NPHP3). ANKS6 has been shown to be important for early renal development and cardiac looping in animal models. Autopsy revealed cystic renal dysplasia and cardiomyocyte hypertrophy, disarray, and focal necrosis. Liver histology revealed cholestasis and centrilobular necrosis, which was likely a result of progressive cardiac failure. This is the first report of compound heterozygous variants in ANKS6 leading to a nephronopthisis-related ciliopathy-like phenotype. We conclude that pathogenic variants in ANKS6 may present early in life with severe renal and cardiac failure, similar to subjects with variants in genes encoding other proteins in the Inv compartment of the cilium.


2020 ◽  
Vol 6 (5) ◽  
pp. e505
Author(s):  
Rodrigo de Holanda Mendonça ◽  
Ciro Matsui ◽  
Graziela Jorge Polido ◽  
André Macedo Serafim Silva ◽  
Leslie Kulikowski ◽  
...  

ObjectiveThe aim of the study was to report the proportion of homozygous and compound heterozygous variants in the survival motor neuron 1 (SMN1) gene in a large population of patients with spinal muscular atrophy (SMA) and to correlate the severity of the disease with the presence of specific intragenic variants in SMN1 and with the SMN2 copy number.MethodsFour hundred fifty Brazilian patients with SMA were included in a retrospective study, and clinical data were analyzed compared with genetic data; the SMN2 copy number was obtained by multiplex ligation-dependent probe amplification and pathogenic variants in SMN1 by next-generation sequencing.ResultsFour hundred two patients (89.3%) presented homozygous exon 7-SMN1 deletion, and 48 (10.7%) were compound heterozygous for the common deletion in one allele and a point mutation in the other allele. Recurrent variants in exons 3 and 6 (c.460C>T, c.770_780dup and c.734_735insC) accounted for almost 80% of compound heterozygous patients. Another recurrent pathogenic variant was c.5C>G at exon 1. Patients with c.770_780dup and c.734_735insC had a clinical phenotype correlated with SMN2 copy number, whereas the variants c.460C>T and c.5C>G determined a milder phenotype independently of the SMN2 copies.ConclusionsPatients with specific pathogenic variants (c.460C>T and c.5C>G) presented a milder phenotype, and the SMN2 copy number did not correlate with disease severity in this group.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Manhua Xu ◽  
Kaiming Li ◽  
Weimin He

Abstract Background Microspherophakia (MSP, OMIM 251,750) is a rare inherited autosomal recessive eye disorder characterized by small spherically shaped lens. Several studies have indicated that the transforming growth factor-beta (TGF-beta) binding proteins(LTBP2) gene mutation is the predominant cause of MSP. In our study, novel compound heterozygous mutations in the LTBP2 gene associated with MSP were reported, which was different from previous reported homozygous mutations. Case presentation The proband was an 18‐year‐old male in Western China with bilateral MSP, accompanied by ectopia lentis, secondary glaucoma and blindness in both eyes. In our hospital, he received bilateral lens resection and trabeculectomy combined with peripheral iridotomy. Using next-generation sequencing (NGS)-based gene panel tests, we identified pathogenic mutations in the peripheral blood DNA sample from the proband: c.3614_3618dupCTGGC (exon24, NM_000428) and c.2819G > A (exon18, NM_000428). The presence of the novel compound heterozygous mutations in the LTBP2 gene was linked with the development of MSP. Sanger sequencing confirmed the existence of one of the two variants in each parent respectively. Conclusion Our results demonstrated a rare case of MSP phenotype associated with novel compound heterozygous mutations in the LTBP2 gene using NGS technology.


2020 ◽  
Author(s):  
Lina Ding ◽  
Yinong Xie ◽  
Tingting Yuan ◽  
Zhen Sui ◽  
Hongzhou Liu ◽  
...  

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