Diagnóstico da Síndrome de Turner: a experiência do Instituto Estadual de Diabetes e Endocrinologia - Rio de Janeiro, de 1970 a 2008

Detection of turner syndrome using hand X-ray using anchor based links segmentation method

Turner Syndrome (TS) is a chromosomal disorder, wherein the female's growth is impacted. Immature ovaries, low stature, and heart abnormalities are a range of developmental and medical issues due to TS. The condition of TS might be detected prior to birth, throughout infancy or in the early years of life. The diagnosis of TS in girls with modest symptoms and indications is sometimes deferred until they reach adolescence or become young adults. This study presents an algorithm to segment the hand digital X-ray image in children with TS. In medical image and computer vision examination, image segmentation is demanding, and very crucial. Prevailing segmentation algorithms even now suffer from common segmentation issues including under-segmentation, over-segmentation, and spurious or non-closed edges, regardless of the several years of studies. In this paper, Anchor Based Link (ABL) segmentation approach is proposed to detect TS based on fourth Metacarpal bone from left hand X-ray images. The detection of TS is demonstrated based upon the comparison of proposed approach with existing watershed segmentation and Gaussian-Mixture-Model-based Hidden-Markov-Random-Field (GMM-HMRF) method. The proposed approach attains better segmentation based on the ratio of height and width of left fourth finger that is analyzed for normal children and children having TS with the help of edge pixel present in the metacarpal bone that has been segmented. The suggested method is verified on fifty (50) sample X-ray hand images of carpal bones, providing 0.60 ± 0.02 as an average Dice coefficient.

Searching chromosome mosaicisms in 45,X Turner syndrome: how relevant is it?

Objective

To investigate the presence of chromosome mosaicism, especially for the presence of Y derived material in 45,X women with Turner syndrome (TS).

Methods

FISH and PCR were performed for the presence of chromosome mosaicism and Y-derived-material and genetic findings were correlated to clinical data.

Results

Thirty-one participants were enrolled: 18 (58%) had chromosome mosaicisms (FISH), Y-derived material was found in 2. Yet, SRY primer was found with PCR in only one of them and DYZ3 was not found. The most frequent clinical findings were short or webbed neck (81,82%), high-arched palate (78%), breast hypertelorism, e cubitus valgus and genu valgus (57.6%, both), short fourth metacarpals (46.9%), epicanthic folds (43.8%), shield chest (43.8%), lymphedema (37.5%), and low set ears (34.4%). Both patients with Y-derived-material had primary amenorrhea, dyslipidemia and reached the height of 150 cm despite not treated with recombinant growth hormone (GHr). One of them showed 26% of leukocytes with Y-derived material and few clinical findings.

Conclusion

FISH techniques proved efficient in detecting chromosome mosaicisms and Y-derived material and searching in different tissues such as mouth cells is critical due to the possibility of tissue-specific mosaicism. Phenotypical variance in TS may be a signal of chromosome mosaicisms, especially with the presence of Y-derived material.

Identification of Y-Chromosome Sequences in Turner Syndrome

OBJECTIVES

To investigate the presence of Y-chromosome sequences and determine their frequency in patients with Turner syndrome.

METHODS

The study included 23 patients with Turner syndrome from Brazil, who gave written informed consent for participating in the study. Cytogenetic analyses were performed in peripheral blood lymphocytes, with 100 metaphases per patient. Genomic DNA was also extracted from peripheral blood lymphocytes, and gene sequences DYZ1, DYZ3, ZFY and SRY were amplified by Polymerase Chain Reaction.

RESULTS

The cytogenetic analysis showed a 45,X karyotype in 9 patients (39.2 %) and a mosaic pattern in 14 (60.8 %). In 8.7 % (2 out of 23) of the patients, Y-chromosome sequences were found. This prevalence is very similar to those reported previously. The initial karyotype analysis of these patients did not reveal Y-chromosome material, but they were found positive for Y-specific sequences in the lymphocyte DNA analysis.

CONCLUSION

The PCR technique showed that 2 (8.7 %) of the patients with Turner syndrome had Y-chromosome sequences, both presenting marker chromosomes on cytogenetic analysis.

[Turner syndrome and genetic polymorphism: a systematic review]

Objective:

To present the main results of the literature on genetic polymorphisms in Turner syndrome and their association with the clinical signs and the etiology of this chromosomal disorder.

Data sources:

The review was conducted in the PubMed database without any time limit, using the terms Turner syndrome and genetic polymorphism. A total of 116 articles were found, and based on the established inclusion and exclusion criteria 17 were selected for the review.

Data synthesis:

The polymorphisms investigated in patients with Turner syndrome were associated with growth deficit, causing short stature, low bone mineral density, autoimmunity and cardiac abnormalities, which are frequently found in patients with Turner syndrome. The role of single nucleotide polymorphisms in the etiology of Turner syndrome, i.e., in chromosomal nondisjunction, was also confirmed.

Conclusions:

Genetic polymorphisms appear to be associated with Turner syndrome. However, in view of the small number of published studies and their contradictory findings, further studies in different populations are needed in order to clarify the role of genetic variants in the clinical signs and etiology of the Turner syndrome.