X-linked hereditary Alport syndrome (XLAS) type 1 (OMIM: 301050) results from a pathogenic variant in the collagen type IV alpha 5 chain (COL4A5) gene.A human induced pluripotent stem cell (iPSC) line was generated from peripheral blood mononuclear cells of a 7-year-old male patient with XLAS using non-integrating episomal vector technique. The male donor had a heterozygous variant in the COL4A5 gene. The resulting iPSC line has a standard karyotype, can express pluripotent biomarkers, and is able to create germ layers in vivo. It can serve as a valuable cellular model for investigating the underlying mechanisms of XLAS.

WNK3 kinase (PRKWNK3) has been implicated in the development and function of the brain via its regulation of the cation-chloride cotransporters, but the role of WNK3 in human development is unknown.
We ascertained exome or genome sequences of individuals with rare familial or sporadic forms of intellectual disability (ID).
We identified a total of 6 different maternally-inherited, hemizygous, 3 loss-of-function or 3 pathogenic missense variants (p.Pro204Arg, p.Leu300Ser, p.Glu607Val) in WNK3 in 14 male individuals from 6 unrelated families. Affected individuals had ID with variable presence of epilepsy and structural brain defects. WNK3 variants cosegregated with the disease in 3 different families with multiple affected individuals. This included 1 large family previously diagnosed with X-linked Prieto syndrome. WNK3 pathogenic missense variants localize to the catalytic domain and impede the inhibitory phosphorylation of the neuronal-specific chloride cotransporter KCC2 at threonine 1007, a site critically regulated during the development of synaptic inhibition.
Pathogenic WNK3 variants cause a rare form of human X-linked ID with variable epilepsy and structural brain abnormalities and implicate impaired phospho-regulation of KCC2 as a pathogenic mechanism.

Dent disease (DD) is a rare X-linked proximal tubulopathy associated with low molecular weight proteinuria (LMWP), hypercalciuria, nephrolithiasis and phosphoruria, which may progress to chronic kidney disease (CKD). About 60% of cases are caused by the mutation in CLCN5 gene. Recently, we identified a mutation in the sequence of homodimer of CLCN5 gene in a patient with DD. The Peripheral Blood Mononuclear Cells (PBMCs) of the patient were obtained and a line of induced pluripotent stem cells (iPSCs) was successfully generated. The iPSC line will be useful for further study of the pathogenesis and drug screening for DD.

X-linked sideroblastic anemia (XLSA) is the most common form of congenital sideroblastic anemia (CSA), and is associated with the mutations in the 5-aminolevulinate synthase 2 (ALAS2). The genetic basis of more than 40% of CSA cases remains unknown.
A two-generation Chinese family with XLSA was studied by next-generation sequencing to identify the underlying CSA-related mutations.
In the study, we identified a missense ALAS2 R204Q mutation in a hemizygous Chinese Han man and in his heterozygous daughter. The male proband presented clinical manifestations at 38 years old and had a good response to pyridoxine.
XLSA, as a hereditary disease, can present clinical manifestations later in lives, for adult male patients with ringed sideroblasts and hypochromic anemia, it should be evaluated with gene analyses to exclude CSA.

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Compound hemizygous variants in SERPINA7 gene.
Thyroxine-binding globulin (TBG) is encoded by SERPINA7 (OMIM. 314200) which is located on Xq22.3. SERPINA7 variants caused TBG deficiency which does not require treatment, but the decreased thyroxine may be misdiagnosed as hypothyroidism. We discovered some variants of TBG caused by alterations that differ from previously reported.
In this study, we enrolled 32 subjects from 10 families and sequenced the SERPINA7 genes of TBG-deficient subjects. Then, variants were analyzed to assess their effect on TBG expression and secretion. Bioinformatics database, protein structure, and dynamics simulation were used to evaluate the deleterious effects. Finally, we identified 2 novel and 4 known variants, and found 26 of 30 subjects carried the p.L303F. The DynaMut predictions indicated the variants (p.E91K, p.I92T, p.R294C, and p.L303F) exhibited decreased stability.
Analyses revealed the p.L303F change the protein stability and flexibility, and it had an impact on the function of TBG, but when coexisted with other variants it might change the conformational structure of the protein and aggravate the damage to the protein. We speculated that the existence of a higher number of variants resulted in lower TBG secretion.

The gene mutations of the chloride channel gene (CLCN5) can lead to the inherited X-linked Dent disease (X-Dent). The urine cells of a 4-year-old male X-Dent patient with the hemizygous CLCN5 gene mutation p.R718* (c.2152C > T) were reprogrammed into induced pluripotent stem cells (iPSCs) using integration free Sendai virus reprogramming system. The generated iPSCs stably expressed pluripotent stem cell markers and can be induced to differentiate into three germ layers in vitro. The karyotype of the generated iPSCs was normal (46, XY).

Xq25 microduplication syndrome is a recognized syndrome presenting intellectual disability and distinctive facial appearance. We generated an induced pluripotent stem cell (iPSC) line from peripheral blood mononuclear cells (PBMCs) of an 8-year-old boy with Xq25 Microduplication Syndrome carrying a 1.3 Mb hemizygote duplication at chrXq25. The iPSCs expressed pluripotency markers, free of genomically integrated episomal plasmids, with normal karyotype and three layers\' differentiation potential in vitro.

Asthenoteratozoospermia characterized by multiple morphological abnormalities of the flagella (MMAF) has been identified as a sub-type of male infertility. Recent progress has identified several MMAF-associated genes with an autosomal recessive inheritance in human affected individuals, but the etiology in approximately 40% of affected individuals remains unknown. Here, we conducted whole-exome sequencing (WES) and identified hemizygous missense variants in the X-linked CFAP47 in three unrelated Chinese individuals with MMAF. These three CFAP47 variants were absent in human control population genome databases and were predicted to be deleterious by multiple bioinformatic tools. CFAP47 encodes a cilia- and flagella-associated protein that is highly expressed in testis. Immunoblotting and immunofluorescence assays revealed obviously reduced levels of CFAP47 in spermatozoa from all three men harboring deleterious missense variants of CFAP47. Furthermore, WES data from an additional cohort of severe asthenoteratozoospermic men originating from Australia permitted the identification of a hemizygous Xp21.1 deletion removing the entire CFAP47 gene. All men harboring hemizygous CFAP47 variants displayed typical MMAF phenotypes. We also generated a Cfap47-mutated mouse model, the adult males of which were sterile and presented with reduced sperm motility and abnormal flagellar morphology and movement. However, fertility could be rescued by the use of intra-cytoplasmic sperm injections (ICSIs). Altogether, our experimental observations in humans and mice demonstrate that hemizygous mutations in CFAP47 can induce X-linked MMAF and asthenoteratozoospermia, for which good ICSI prognosis is suggested. These findings will provide important guidance for genetic counseling and assisted reproduction treatments.

X-linked retinoschisis (XLRS) is one type of retinal dystrophy leading to the schisis of the neural retina and causing reduced visual acuity. The study aimed to investigate the clinical manifestations and retinoschisin 1 (RS1) mutations in Chinese patients with early onset XLRS.
Thirty-eight probands with early onset XLRS were recruited, comprehensive ophthalmic examination was performed. A targeted gene panel was used to test the RS1 mutations.
All probands had RS1 hemizygous mutations including 16 known and 14 novel mutations. The median onset age was 2 years old (range 0.1-6 years). Probands with onset age ≤1 years. had more complications (retinal detachment and vitreous hemorrhage, p < 0.001), more mutations outside the discoidin domain and more non-frameshift mutations than probands with onset age >1 years. Macular and peripheral involvement was present in 77.27% of probands, and inner and outer nuclear layer splitting were present in 53.57% of probands. Electroretinography showed an electronegative waveform. The relatively rare phenotypes of lamellar macular hole and macular hole were present in a unilateral eye in three probands.
In conclusion, the early onset XLRS developed more severe complications which need close monitoring and clinical manifestations illustrated here may facilitate the early diagnosis of retinoschisis.