Bi-Allelic c.1746G>T; p.Leu582= Variants in TUBGCP4 in a Boy with Autism: Clinical Data and Literature Review

2021 ◽  
pp. 1-6
Author(s):  
Daniel Martín Fernández-Mayoralas ◽  
Jacobo Albert ◽  
Sara López-Martín ◽  
Mar Jiménez de la Peña ◽  
Ana Laura Fernández-Perrone ◽  
...  

Bi-allelic mutations in the <i>TUBGCP4</i> gene have been recently associated with autosomal recessive microcephaly with chorioretinopathy. However, little is known about the genotype-phenotype characteristics of this disorder. Here, we describe a 5-year-old male patient with autism and a normal occipitofrontal circumference. No retinal abnormalities were observed. Brain MRI revealed the presence of enlarged sheaths of both tortuous optic nerves; both eyes had shorter axial lengths. Whole-exome sequencing in trio revealed synonymous <i>TUBGCP4</i> variants in homozygous state: c.1746G&#x3e;T; p.Leu582=. This synonymous variant has been previously described and probably leads to skipping of exon 16 of <i>TUBGCP4</i>. These results broaden the clinical spectrum of this new syndrome and suggest that <i>TUBGCP4</i> bi-allelic mutations may underlie complex neurodevelopmental disorders.

2020 ◽  
Vol 10 (1) ◽  
pp. 88-92
Author(s):  
T. V. Markova ◽  
A. O. Borovikov ◽  
E. R. Lozier ◽  
A. A. Isaev ◽  
V. S. Kaimonov ◽  
...  

Early epileptic encephalopathy-66 was first diagnosed in a male patient from Russia using whole-exome sequencing. Early epileptic encephalopathy- 66 is a unique disorder in the group of early epileptic encephalopathies. The same recurrent heterozygous variant of the nucleotide sequence was found in all known patients, but the severity of seizures and dysmorphic signs significantly vary between patients. The current study of a recurrent pathogenic variant in PACS2 gene expands the phenotype spectrum of early epileptic encephalopathy-66 and will improve the management of patients with that disorder in Russia in the future.


2017 ◽  
Vol 27 (4) ◽  
pp. 614-624 ◽  
Author(s):  
Monika Weisz Hubshman ◽  
Sanne Broekman ◽  
Erwin van Wijk ◽  
Frans Cremers ◽  
Alaa Abu-Diab ◽  
...  

2020 ◽  
Vol 14 (2) ◽  
pp. 83-88
Author(s):  
Phawin Kor-anantakul ◽  
Kanya Suphapeetiporn ◽  
Somchit Jaruratanasirikul

AbstractAblepharon macrostomia syndrome (AMS) is a rare congenital disorder. To our knowledge, only 20 cases have been reported to date, and all in patients from Western countries. We report a case of AMS in a Thai patient, who presented at age 3 months with severe ectropion of both upper and lower eyelids, alopecia totalis, no palpable clitoris, and hypoplasia of both labia minora and labia majora. Trio whole exome sequencing analysis was performed, which revealed a heterozygous missense c.223G>A (p.Glu75Lys) variation in TWIST2. To our knowledge, this is the first reported case of AMS in a patient from Thailand and the first reported case of AMS in Asia.


2021 ◽  
Author(s):  
Rui Zhang ◽  
Yajing Hao ◽  
Ying Xu ◽  
Jiale Qin ◽  
Yanfang Wang ◽  
...  

Abstract Background: Isolated sulfite oxidase deficiency (ISOD) is the rarest types of life-threatening neurometabolic disorders characterized by neonatal intractable seizures and severe developmental delay with an autosomal recessive mode of inheritance. ISOD is extremely rare and till date only 32 mutations have been identified and reported worldwide. Germline mutation in SUOX gene causes ISOD. Methods: Here, we investigated a 5-days old Chinese female child, presented with intermittent tremor or seizures of limbs, neonatal encephalopathy, subarachnoid cyst and haemorrhage, dysplasia of corpus callosum, neonatal convulsion, respiratory failure, cardiac failure, hyperlactatemia, severe metabolic acidosis, hyperglycemia, hyperkalemia, moderate anemia, atrioventricular block and complete right bundle branch block. Results: Whole exome sequencing identified a novel homozygous transition (c.1227G>A) in exon 6 of the SUOX gene in the proband. This novel homozygous variant leads to the formation of a truncated sulfite oxidase (p.Trp409*) of 408 amino acids. Hence, it is a loss-of-function variant. Proband’s father and mother is carrying this novel variant in a heterozygous state. This variant was not identified in 200 ethnically matched normal healthy control individuals. Conclusions: Our study not only expand the mutational spectrum of SUOX gene associated ISOD, but also strongly suggested the application of whole exome sequencing for identifying candidate genes and novel disease-causing mutations.


2020 ◽  
Author(s):  
Pengfei Liang ◽  
Fengping Chen ◽  
Shujuan Wang ◽  
Qiong Li ◽  
Wei Li ◽  
...  

Abstract Background: Hereditary non-syndromic hearing loss (NSHL) has a high genetic heterogeneity with >152 genes identified as associated molecular causes. The present study aimed to detect the possible damaging variants of the deaf probands from six unrelated Chinese families.Methods: After excluding the mutations in the most common genes, GJB2 and SLC26A4, 12 probands with prelingual deafness and autosomal recessive inheritance were evaluated by whole-exome sequencing (WES). All the candidate variants were verified by Sanger sequencing in all patients and their parents.Results: Biallelic mutations were identified in all deaf patients. Among these six families, 10 potentially causative mutations, including 3 reported and 7 novel mutations, in 3 different deafness-associated autosomal recessive (DFNB) genes (MYO15A, COL11A2, and CDH23) were identified. The mutations in MYO15A were frequent with 7/10 candidate variants. Sanger sequencing confirmed that these mutations segregated with the hearing loss of each family.Conclusions: Next-generation sequencing (NGS) approach becomes more cost-effective and efficient when analyzing large-scale genes compared to the conventional polymerase chain reaction-based Sanger sequencing, which is often used to screen common deafness-related genes. The current findings further extend the mutation spectrum of hearing loss in the Chinese population, which has a positive significance for genetic counseling.


Author(s):  
Piranit Nik Kantaputra ◽  
Prapai Dejkhamron ◽  
Worrachet Intachai ◽  
Chumpol Ngamphiw ◽  
Katsushige Kawasaki ◽  
...  

Summary Background Juberg-Hayward syndrome (JHS; MIM 216100) is a rare autosomal recessive malformation syndrome, characterized by cleft lip/palate, microcephaly, ptosis, short stature, hypoplasia or aplasia of thumbs, and dislocation of radial head and fusion of humerus and radius leading to elbow restriction. Objective To report for the first time the molecular aetiology of JHS. Patient and methods Clinical and radiographic examination, whole exome sequencing, Sanger sequencing, mutant protein model construction, and in situ hybridization of Esco2 expression in mouse embryos were performed. Results Clinical findings of the patient consisted of repaired cleft lip/palate, microcephaly, ptosis, short stature, delayed bone age, hypoplastic fingers and thumbs, clinodactyly of the fifth fingers, and humeroradial synostosis leading to elbow restriction. Intelligence is normal. Whole exome sequencing of the whole family showed a novel homozygous base substitution c.1654C&gt;T in ESCO2 of the proband. The sister was homozygous for the wildtype variant. Parents were heterozygous for the mutation. The mutation is predicted to cause premature stop codon p.Arg552Ter. Mutations in ESCO2, a gene involved in cohesin complex formation, are known to cause Roberts/SC phocomelia syndrome. Roberts/SC phocomelia syndrome and JHS share similar clinical findings, including autosomal recessive inheritance, short stature, cleft lip/palate, severe upper limb anomalies, and hypoplastic digits. Esco2 expression during the early development of lip, palate, eyelid, digits, upper limb, and lower limb and truncated protein model are consistent with the defect. Conclusions Our study showed that Roberts/SC phocomelia syndrome and JHS are allelic and distinct entities. This is the first report demonstrating that mutation in ESCO2 causes JHS, a cohesinopathy.


2018 ◽  
Vol 55 (3) ◽  
pp. 198-204 ◽  
Author(s):  
Wen-Bin He ◽  
Chao-Feng Tu ◽  
Qiang Liu ◽  
Lan-Lan Meng ◽  
Shi-Min Yuan ◽  
...  

BackgroundThe genetic causes of the majority of male and female infertility caused by human non-obstructive azoospermia (NOA) and premature ovarian insufficiency (POI) with meiotic arrest are unknown.ObjectiveTo identify the genetic cause of NOA and POI in two affected members from a consanguineous Chinese family.MethodsWe performed whole-exome sequencing of DNA from both affected patients. The identified candidate causative gene was further verified by Sanger sequencing for pedigree analysis in this family. In silico analysis was performed to functionally characterise the mutation, and histological analysis was performed using the biopsied testicle sample from the male patient with NOA.ResultsWe identified a novel homozygous missense mutation (NM_007068.3: c.106G>A, p.Asp36Asn) in DMC1, which cosegregated with NOA and POI phenotypes in this family. The identified missense mutation resulted in the substitution of a conserved aspartic residue with asparaginate in the modified H3TH motif of DMC1. This substitution results in protein misfolding. Histological analysis demonstrated a lack of spermatozoa in the male patient’s seminiferous tubules. Immunohistochemistry using a testis biopsy sample from the male patient showed that spermatogenesis was blocked at the zygotene stage during meiotic prophase I.ConclusionsTo the best of our knowledge, this is the first report identifying DMC1 as the causative gene for human NOA and POI. Furthermore, our pedigree analysis shows an autosomal recessive mode of inheritance for NOA and POI caused by DMC1 in this family.


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