Monoallelic pathogenic HMBS variants are a well-established cause of acute intermittent porphyria (AIP), whereas biallelic pathogenic variants may cause HMBS-related leukoencephalopathy which remains a poorly characterized disorder. We describe an 8-year-old girl with hypotonia, hearing impairment, horizontal nystagmus, bilateral strabismus, impaired visual acuity, and optic nerve atrophy. She had no epilepsy but sleep electroencephalogram showed paroxysmal changes in the right hemisphere with secondary generalizations. Brain magnetic resonance imaging was unremarkable apart from a few small white matter hyperintensities. Exome sequencing (ES) initially prioritized a SCN3A c.3822G>A de novo variant whose sole causative role was eventually questioned as not fully compatible with symptoms. ES reanalysis revealed a homozygous c.674G>A HMBS variant. In the monoallelic form this variant is a known cause of AIP, whereas in trans with another HMBS pathogenic variant it was associated with the HMBS-related leukoencephalopathy in four individuals. Despite lack of signs/symptoms of porphyria, literature analysis suggested that HMBS c.674G>A likely contributed to the disease either as the sole cause or together with SCN3A c.3822G>A as a part of blended phenotype. Our report adds to the relatively small number of described cases of HMBS-related leukoencephalopathy and emphasizes that autosomal recessive form of HMBS disease can be present in the absence of porphyria symptoms.

UNASSIGNED: Lipoprotein lipase (LPL) is an important enzyme in lipid metabolism, individuals with LPL gene variants could present type I hyperlipoproteinemia, lipemia retinalis, hepatosplenomegaly, and pancreatitis. To date, there are no reports of renal lipidosis induced by type I hyperlipoproteinemia due to LPL mutation.
UNASSIGNED: Renal biopsy was conducted to confirm the etiological factor of nephrotic syndrome in a 44-year-old Chinese man. Lipoprotein electrophoresis, apoE genotype detection, and whole-exome sequencing were performed to confirm the dyslipidemia type and genetic factor. Analysis of the 3-dimensional protein structure and in vitro functional study were conducted to verify variant pathogenicity.
UNASSIGNED: Renal biopsy revealed numerous CD68 positive foam cells infiltrated in the glomeruli; immunoglobulin and complement staining were negative; and electron microscopy revealed numerous lipid droplets and cholesterol clefts in the cytoplasm of foam cells. Lipoprotein electrophoresis revealed that the patient fulfilled the diagnostic criteria of type I hyperlipoproteinemia. The apoE genotype of the patient was the ε3/ε3 genotype. Whole-exome sequencing revealed an LPL (c.292G > A, p.A98T) homozygous variant with α-helix instability and reduced post-heparin LPL activity but normal lipid uptake capability compared to the wild-type variant.
UNASSIGNED: LPL (c.292G > A, p.A98T) is a pathogenic variant that causes renal lipidosis associated with type I hyperlipoproteinemia. This study provides adequate evidence of the causal relationship between dyslipidemia and renal lesions. However, further research is needed to better understand the pathogenetic mechanism of LPL variant-related renal lesions.

UNASSIGNED: Developmental and epileptic encephalopathies (DEEs) signify a group of heterogeneous neurodevelopmental disorder associated with early-onset seizures accompanied by developmental delay, hypotonia, mild to severe intellectual disability, and developmental regression. Variants in the DNM1 gene have been associated with autosomal dominant DEE type 31A and autosomal recessive DEE type 31B.
UNASSIGNED: In the current study, a consanguineous Pakistani family consisting of a proband (IV-2) was clinically evaluated and genetically analyzed manifesting in severe neurodevelopmental phenotypes. WES followed by Sanger sequencing was performed to identify the disease-causing variant. Furthermore, 3D protein modeling and dynamic simulation of wild-type and mutant proteins along with reverse transcriptase (RT)-based mRNA expression were checked using standard methods.
UNASSIGNED: Data analysis of WES revealed a novel homozygous non-sense variant (c.1402G>T; p. Glu468*) in exon 11 of the DNM1 gene that was predicted as pathogenic class I. Variants in the DNM1 gene have been associated with DEE types 31A and B. Different bioinformatics prediction tools and American College of Medical Genetics guidelines were used to verify the identified variant. Sanger sequencing was used to validate the disease-causing variant. Our approach validated the pathogenesis of the variant as a cause of heterogeneous neurodevelopmental disorders. In addition, 3D protein modeling showed that the mutant protein would lose most of the amino acids and might not perform the proper function if the surveillance non-sense-mediated decay mechanism was skipped. Molecular dynamics analysis showed varied trajectories of wild-type and mutant DNM1 proteins in terms of root mean square deviation, root mean square fluctuation and radius of gyration. Similarly, RT-qPCR revealed a substantial reduction of the DNM1 gene in the index patient.
UNASSIGNED: Our finding further confirms the association of homozygous, loss-of-function variants in DNM1 associated with DEE type 31B. The study expands the genotypic and phenotypic spectrum of pathogenic DNM1 variants related to DNM1-associated pathogenesis.

This case report explores the rare association of recurrent meningitis, hydrocephalus, ligneous conjunctivitis, and congenital plasminogen deficiency in a term baby boy. Born at 39 weeks with a history of hydrocephalus, the neonate later developed ligneous conjunctivitis and a serious bout of meningitis. Genetic analyses confirmed a homozygous mutation in the PLG gene, indicative of congenital plasminogen deficiency. Despite intensive treatment, including a ventriculoperitoneal shunt for hydrocephalus and intravenous antibiotics for meningitis, the child succumbed to upper airway obstruction before reaching one year of age. This report underscores the medical complexity and severity of these interconnected conditions and advocates for further research to understand the interplay between them. Although this study is limited by its single-case nature and is not generalizable, it emphasizes the necessity for early recognition and a multidisciplinary treatment approach for better patient outcomes.

Hereditary transthyretin amyloidosis is a severe, adult-onset autosomal dominant inherited systemic disease predominantly affecting the peripheral and autonomic nervous system, heart, kidney, and the eyes. We present a case of a Caucasian 65-year-old man with cardiac amyloidosis and the homozygous mutation Val142Ile (classically, Val122Ile) in the transthyretin gene. We provide a genotype-phenotype correlation regarding the genetic status of both heterozygous and homozygous individuals and their clinical conditions at the time of genetic testing.

UNASSIGNED: The polymorphic variations of human telomerase reverse transcriptase (hTERT) gene play an important role in predisposition to carcinogenesis. The current study aimed to elucidate the genetic predisposition to bladder cancer in two important variants, rs2736098 and rs2736100 of hTERT gene.
UNASSIGNED: Confirmed 130 patients of bladder cancer and 200 healthy controls were genotyped by PCR-RFLP to determine different variants of hTERT rs2736098 and rs2736100.
UNASSIGNED: hTERT rs2736098 homozygous variant AA genotype frequency was observed to significantly differ 2-fold between cases and controls (26.15% vs. 13.5%) (p = 0.02). In addition, rare \'A\' allele significantly differed among two groups (cases: 47% versus controls: 39%: p = 0.03). hTERT rs2736098 was observed to be presented significantly more in high stage tumors (p = 0.02). hTERT rs2736100 genotype AA or variant allele A showed no significant difference between cases and controls. Haplotype CA displayed significantly different pattern of frequency as 0.5 in cases as compared to 0.16 in controls (p < 0.0001). Combination of variant A/G haplotype frequency implicated more in cases than in controls (0.34 vs. 0.14, p = 0.001).
UNASSIGNED: It is concluded that hTERT rs2736098 polymorphic variant has a vital role to confer a strong risk to bladder cancer in our population. Further, hTERT haplotypes CA and AG inhTERT could prove to be a promising tool to screen the risk for bladder cancer.

The Ehlers-Danlos syndrome (EDS) is a group of heritable connective tissue disorders. Common features of EDS include skin hyperextensibility, articular hypermobility, and tissue fragility. It is classified into 13 subtypes, caused by variations of more than 19 different genes. Among these two subtypes, EDS musculocontractural type 1 (EDSMC1/mcEDS-CHST14; MIM# 601776) is caused by biallelic mutations in the CHST14 gene (MIM# 608429) on chromosome 15q14 and EDS musculocontractural type 2 (EDSMC2/mcEDS-DSE;MIM#615539) is caused by a mutation in DSE (MIM# 605942) on chromosome 6q22. In this study, clinical and molecular diagnoses have been performed for a consanguineous Pakistani (Pakhtun) family with five affected siblings, presenting mcEDS-DSE phenotype. Whole-exome sequencing analysis identified a novel homozygous DSE variant (NM_001080976.1; c.2813T>A, p.Val938Asp) in the proband. Sanger sequencing in all available affected members and their obligate carriers confirmed autosomal recessive segregation of the diseased allele. To the best of our knowledge, this variant identified is novel and expands the DSE pathogenicity leading to EDS, musculocontractural type 2. The result obtained has the potential to help in early diagnosis, genetic counseling, and possible therapeutic inventions.

[This corrects the article DOI: 10.3389/fnins.2021.604715.].

Chorea-Acanthocytosis (ChAc), a rare autosomal recessive inherited neurological disorder, originated from variants in Vacuolar Protein Sorting 13 homolog A (VPS13A) gene. The main symptoms of ChAc contain hyperkinetic movements, seizures, cognitive impairment, neuropsychiatric symptoms, elevated serum biochemical indicators, and acanthocytes detection in peripheral blood smear. Recently, researchers found that epilepsy may be a presenting and prominent symptom of ChAc. Here, we enrolled a consanguineous family with epilepsy and non-coordinated movement. Whole exome sequencing was employed to explore the genetic lesion of the family. After data filtering, co-separation analysis was performed by Sanger sequencing and bioinformatics analysis, the homozygous nonsense variant (NM_033305.2: c.8282C>G, p.S2761X) of VPS13A were identified which could be genetic factor of the patient. No other meaningful mutations were detected. This mutation (p.S2761X) led to a truncated protein in exon 60 of the VPS13A gene, was simultaneously absent in our 200 local control participants. The homozygous mutation (NM_033305.2: c.8282C>G, p.S2761X) of VPS13A may be the first time be identified in ChAc patient with epilepsy. Our study assisted to the diagnosis of ChAc in this patient and contributed to the genetic diagnosis and counseling of families with ChAc presented as epilepsy. Moreover, we further indicated that epilepsy was a crucial phenotype in ChAc patients caused by VPS13A mutations.

The enzyme NOP2/Sun RNA methyltransferase 2 (NSUN2) catalyzes the methylation of cytosine to 5-methylcytosine (m5C) at position 34 of tRNA(Leu; CAA) precursors containing introns that play a vital role in spindle assembly during mitosis and chromosome segregation. Biallelic variants in the NSUN2 gene cause a rare intellectual disability that has been identified only in a few Middle Eastern patients. Affected individuals usually have other deformities, including developmental delay, short stature, microcephaly, and facial dysmorphism. The aim of this study was to identify the genetic cause of three female patients from a Chinese pedigree, who presented with similar phenotype consisting of the above clinical features.
Whole-exome sequencing (WES) was used to screen for causal variants in the genome, and the candidate variants were subsequently verified using Sanger sequencing.
WES revealed a previously unreported homozygous nonsense variant (NM_017755.5: c.1004T>A, p.Leu335*) in exon 9 of NSUN2, which was consistent with the clinical phenotype of the patients and co-segregated with the disease in their family. A comparison of this phenotype with that of patients in published reports uncovered several novel clinical features related to NSUN2 variations, including feeding difficulties, slender hands and fingers, severely restricted finger mobility, hallux valgus, varus foot, and elevated α-hydroxybutyrate dehydrogenase (HBDH).
These are the first findings of a non-consanguineous Chinese pedigree with a homozygous NSUN2 variant. We expanded the phenotypic spectrum associated with NSUN2 variations.