Search results for "X chromosome"

Pigmentary mosaicism in hypomelanosis of Ito

1998

We report on a female with mental and motor retardation, facial dysmorphism, abnormal pigmentation reminiscent to hypomelanosis of Ito (HI), and karyotypic mosaicism involving a small supernumerary marker chromosome. The marker chromosome was defined by fluorescence in situ hybridisation (FISH) as a ring X chromosome with breakpoints in the juxtacentromeric region. FISH analysis showed that the ring does not include the XIST locus at the X-inactivation centre and, therefore, may not be subject to X inactivation. X-inactivation studies with the HUMARA (human androgen receptor) and FMR1 assay showed a skewed X-inactivation pattern (85:15) with preferential inactivation of the paternal X chrom…

[Y chromosome in Turner syndrome].

2017

Turner syndrome (TS) is an inherited genetic disorder caused by numerical and/or structural chromosome X aberrations occurring at a frequency of 1:1200-1:2500 live-born girls. The most common karyotype is X chromosome monosomy (45,X) (approximately 50-60% of cases). Approximately 5-6% of patients may have abnormal Y chromosome or mosaicism characterized by the coexistence of 45,X cell line with cell line in which all or part of chromosome Y is present. In patients with TS who have all or fragmented genetic material from chromosome Y there is a substantial risk of cancerous lesions in these dysgenetic gonads. This paper stands for the review of the current knowledge on the genetic material o…

Development of a quadruplex PCR system for the genetic analysis of X-chromosomal STR loci

2003

Short tandem repeat systems on the X chromosome are the natural counterpart to the well-established Y-chromosomal STR loci. The X-linked systems are inherited as a single haplotype only in males, whereas in females, the X chromosomes recombine and exhibit the same characteristics as the autosomes. Nevertheless, X-linked systems may provide a useful tool in paternity cases with female offspring, in particular when the alleged father is not available for testing, or in forensic identification cases based on the comparison with firstor second-degree relatives. Only a small number of STR loci have been described on the X chromosome, and a number of these are not highly informative. Therefore, w…

Screening for microdeletions of the X-chromosome in non-specific mental retardation

2003

Girl With Partial Turner Syndrome and Absence Epilepsy

2007

This report describes a 16-year-old girl with short stature (-5 standard deviations), normal puberty, panic attacks, absence epilepsy, some stigmata of Turner syndrome, and a Madelung deformity. Routine chromosomal analysis revealed a female karyotype with one abnormal chromosome X, with the suspicion of additional material on the short arm. With fluorescent in situ hybridization and array-multiplex amplifiable probe hybridization methodology, a complex aberration was detected, with a deletion of the distal part of Xp22.33 (including the short-stature homeobox gene) and a duplication of Xp22.32-p22.12 proximal to the deleted segment. The deletion in our patient involves the Xp22.33 region. …

Mapping Retrotransposon LINE-1 Sequences into Two Cebidae Species and Homo sapiens Genomes and a Short Review on Primates

2022

This work focuses on the distribution of LINE-1 (a Long Interspersed Nuclear Element) in primates and its role during evolution and as a constituent of the architecture of primate genomes. To pinpoint the LINE-1 repeat distribution and its role among primates, LINE-1 probes were mapped onto chromosomes of Homo sapiens (Hominidae, Catarrhini), Sapajus apella, and Cebus capucinus (Cebidae, Platyrrhini) using fluorescence in situ hybridisation (FISH). The choice of platyrrhine species are due to the fact they are taxa characterised by a high level of rearrangements; for this reason, they could be a useful model for the study of LINE-1 and chromosome evolution. LINE-1 accumulation was found in …

Changes in sex ratio from fertilization to birth in assisted-reproductive-treatment cycles

2014

Background: In Western gender-neutral countries, the sex ratio at birth is estimated to be approximately 1.06. This ratio is lower than the estimated sex ratio at fertilization which ranges from 1.07 to 1.70 depending on the figures of sex ratio at birth and differential embryo/fetal mortality rates taken into account to perform these estimations. Likewise, little is known about the sex ratio at implantation in natural and assisted-reproduction-treatment (ART) cycles. In this bioessay, we aim to estimate the sex ratio at fertilization and implantation using data from embryos generated by standard in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) in preimplantation gene…

Rapid detection of an Angiotensin Type 2 Receptor Gene variant: no evidence for linkage and association with primary vesicoureteral reflux

2000

Primary vesicoureteral reflux (VUR) affects approximately 1−2% of the general population and is a common cause of end-stage renal failure in children. VUR appears to have a genetic basis and several loci including the Angiotensin Type 2 Receptor Gene (AGTR2) on the X chromosome have been suggested. Using single-strand conformation analysis (SSCA) we typed 103 DNA samples from 17 families with two or more affected individuals for the presence of a splice site mutation in the AGTR2 gene. Linkage analysis revealed a parametric LOD score of −3.977 and a NPL-score of −6,522 by affected-only analysis. Our family-data do not support linkage of VUR to the AGTR2.

Clinical, immunological, and molecular analysis in a large cohort of patients with X-linked agammaglobulinemia: an Italian multicenter study

2002

A questionnaire-based retrospective clinical and immunological survey was conducted in 73 males with a definite diagnosis of X-linked agammaglobulinemia based on BTK sequence analysis. Forty-four were sporadic and 29 familial cases. At December 2000, the patients' ages ranged from 2 to 33 years; mean age at diagnosis and mean duration of follow-up were 3.5 and 10 years respectively. After the mid-1980s all but 2 were on intravenous immunoglobulin (IVIG) substitution therapy, with residual IgG >500 mg/dl in 94% of the patients at the time of enrollment. Respiratory infections were the most frequent manifestation both prior to diagnosis and over follow-up. Chronic lung disease (CLD) was prese…

Genomic characterization of the Atlantic cod sex-locus

2016

AbstractA variety of sex determination mechanisms can be observed in evolutionary divergent teleosts. Sex determination is genetic in Atlantic cod (Gadus morhua), however the genomic location or size of its sex-locus is unknown. Here, we characterize the sex-locus of Atlantic cod using whole genome sequence (WGS) data of 227 wild-caught specimens. Analyzing more than 55 million polymorphic loci, we identify 166 loci that are associated with sex. These loci are located in six distinct regions on five different linkage groups (LG) in the genome. The largest of these regions, an approximately 55 Kb region on LG11, contains the majority of genotypes that segregate closely according to a XX-XY s…