Identified novel heterozygous HTRA1 pathogenic variants in Chinese patients with HTRA1-associated dominant cerebral small vessel disease.

Background: Homozygous and compound heterozygous mutations in HTRA1 cause cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL). Recently, heterozygous pathogenic variants in HTRA1 were described in patients with autosomal dominant cerebral small vessel disease (CSVD). Here, we investigated the genetic variants in a cohort of Chinese patients with CSVD. Methods: A total of 95 Chinese index patients with typical characteristics of CSVD were collected. Whole exome sequencing was performed in the probands, followed by Sanger sequencing. Pathogenicity prediction software was applied to evaluate the pathogenicity of the identified variants. Results: We detected five heterozygous HTRA1 pathogenic variants in five index patients. These pathogenic variants included four known variants (c.543delT, c.854C>T, c.889G>A, and c.824C>T) and one novel variant (c.472 + 1G>A). Among them, c.854C>T, c.824C>T, and c.472 + 1G>A have never been reported in China and c.889G>A was once reported in homozygous but never in heterozygous. Three of them were distributed in exon 4, one in exon 2, and another splicing variant in intron 1. Four out of five probands presented typical features of CARASIL but less severe. The common clinical features included lacunar infarction, cognitive decline, alopecia, and spondylosis. All of them showed leukoencephalopathy, and the main involved cerebral area include periventricular and frontal area, centrum semiovale, thalamus, and corpus callosum. Anterior temporal lobes and external capsule involvement were also observed. Three probands had intracranial microbleeds. Conclusion: Our study expanded the mutation spectrum of HTRA1, especially in Chinese populations, and provided further evidence for "hot regions" in exon 1-4, especially in exon 4, in heterozygous HTRA1 pathogenic variants. Our work further supported that patients with heterozygous HTRA1 pathogenic variants presented with similar but less-severe features than CARASIL but in an autosomal dominantly inherited pattern.

Common genetic variants in PRRC2A are associated with both neuromyelitis optica spectrum disorder and multiple sclerosis in Han Chinese population.

BACKGROUND: The proline-rich coiled-coil 2A (PRRC2A) gene has been reported to underlie risk of various autoimmune diseases. However, no data reveal the risk susceptibility of PRRC2A to neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS) so far. OBJECTIVES: To explore the association between PRRC2A variants and NMOSD and MS susceptibility in Han Chinese population. METHODS: Totally, 207 NMOSD (98 AQP4+ and 109 AQP4-) patients, 141 MS and 196 healthy controls (HC) were enrolled. Candidate tagging single nucleotide polymorphisms (tag-SNPs) were selected from the 1000G database based on the Chinese data. SNP genotyping was performed using MassArray and Sanger sequencing. RESULTS: PRRC2A variants rs2736171, rs2736157, rs2844470 alter susceptibility to AQP4+ NMOSD, while rs2242659 to MS. Genotype AT of rs2844470 and AG of rs2242659 increased risk susceptibility for AQP4+ NMOSD and MS, respectively. AQP4+ NMOSD exhibited a higher frequency of genotype AG of rs2736157 compared with AQP4- NMOSD. Haplotype TCAAGGTAG was conferred risk susceptibility to AQP4+ NMOSD and haplotype TTAGAGTAG had a protective effect on both AQP4+ and AQP4- NMOSD. Further, we identified various gene expression levels in disease-related regions that are significantly modulated by three cis-eQTL SNPs rs2736157, rs2736171 and rs2242659 (p < 1.05 × 10-4). CONCLUSIONS: PRRC2A variants are first reported to be associated with NMOSD and MS. The identified PRRC2A variants may shed light on the pathogenesis of NMOSD and MS and potentially lead to an individualized therapeutic approach for both distinct disease entities.

Spastic paraplegia as the predominant phenotype in a cohort of Chinese patients with adrenoleukodystrophy.

BACKGROUND: X-linked adrenoleukodystrophy (ALD) is one of the most common peroxisomal disorders characterized by abnormal accumulation of very long-chain fatty acids (VLCFA) in plasma and tissues and caused by mutations within ABCD1. Clinically, ALD present with various phenotypes, ranging from asymptomatic type to rapidly progressive childhood cerebral form. However, no remarkable abnormality in cerebral white matter usually makes it difficult to distinguish adult ALD from hereditary spastic paraplegia (HSP). METHODS: We analyzed the features of seven Chinese ALD patients who had a primary phenotype of spastic paraplegia. Sequencing was performed in the probands and their familial members. Detailed clinical, VLCFAs test, hormone test, magnetic resonance imaging, and electromyogram are presented. RESULTS: We reported seven ALD patients from a Chinese cohort of 142 HSP patients. Genetic investigations revealed five known ABCD1 mutations (c.346G>C, c.521A>G, c.829G>T, c.1415_1416delAG, and c.1849C>T) and two novel mutations (c.454C>G, c.1452_1482del). Further auxiliary testing revealed that they had higher VLCFA and/or adrenal insufficiency. CONCLUSIONS: Our findings expand the mutation spectrum of ABCD1 and indicate that ALD represent a significant portion (4.9%, 7/142) of the spastic paraplegia entities. ALD should be considered in male patients with spastic paraplegia, even if there was no positive family history.

Trigeminal Autonomic Cephalalgias Manifested As The Only Initial Symptom Of Ehlers-Danlos Syndrome Type IV.

Ehlers-Danlos syndrome (EDS) type IV is characterized by thin skin with visible veins, easy bruising, characteristic facial features, arterial and digestive complications, as well as rupture of the gravid uterus. It has never been previously reported that trigeminal autonomic cephalalgias (TACs) could manifest as the only initial symptom of EDS type IV. Here, we report a case of a 27-year-old man who presented atypical headache like TACs stimulated by right internal carotid artery dissection. About one month after his discharge, he suffered dissection of the right renal artery and splenic artery, in addition to partial infarction of the right kidney and spleen. Genetic testing revealed a novel splicing variant c.799-1G>A within COL3A1. He was ultimately diagnosed with Ehlers-Danlos syndrome type IV. This case expanded the genetic spectrum and clinical manifestation of EDS type IV and provided a significant implication for the diagnosis of EDS type IV when the initial symptom manifested as TACs, not the typical presentation of EDS type IV.

Clinical and genetic characterization of a cohort of Chinese patients with hereditary spastic paraplegia.

Pedigree chart of hereditary spastic paraplegia (HSP) patients and chromatogram of novel mutations. A. Pedigree chart of 12 Chinese HSP families with mutation. Squares indicate males; circles indicate females; the black symbols indicate affected individuals; arrows indicate the probands; and asterisks indicate the individual with mutation.B. Chromatogram of six novel mutations identified in our cohort. The upper panel in chromatogram depicts the reference sequence. The lower panel represents heterozygous mutated sequence.