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Ring chromosome 13 is a rare genetic condition with an incidence of 1/58,000 in live births. Major clinical features of patients with ring chromosome 13 include growth and developmental retardation, microcephaly, facial dysmorphism, ambiguous genitalia, anal atresia, eye malformations, retinoblastoma, and hand, foot, and toe abnormalities. The severity of the phenotype depends on the amount of genetic material lost during ring chromosome formation. Here, we report 2 cases with ring chromosome 13 at either end of the phenotypic spectrum. [ABSTRACT FROM AUTHOR]

Objective: The objective of the present study was to describe the phenotypic features of Turner syndrome (TS) and to investigate the relationship between the genotype and the phenotype. Materials and Methods: We studied 26 female patients who were enrolled between 2006 and 2015. Physical features, clinical history, laboratory findings, and imaging test results were recorded. Chromosomal analysis was performed on peripheral blood lymphocyte cultures of the patients. Results: The mean age of the study population was 10.4±5.6 years (range, 1 day to 17 years). Three patients were diagnosed in the neonatal period. Although the most common phenotypic feature was short stature (92.3%), the characteristic stigmatas were usually seen in the 45, X karyotype. Among the 26 patients, monosomy 45, X was detected in 7 (26.9%) of them. Eleven percent of our patients had 46,X,i(X) (isochromosome Xq), while the rest demonstrated mosaic karyotypes [45,X/46,XY (19.2%); 45,X/46,XX (11.5%); 45,X/46,X,i(X) (11.5%); 45,X/46,XX,r(X) (7.7%); 45,X/46,X,i(Y) (3.8%); 45,X/47,XXX (3.8%); and 45,X/46,XX del(Xp) (3.8%)]. Conclusion: TS is one of the most common sex chromosome abnormalities, but it is frequently underdiagnosed. The frequency of the monosomy 45, X karyotype in TS is less than previously thought. Therefore, patients should be evaluated by chromosome analysis in case there is clinical suspicion. [ABSTRACT FROM AUTHOR]

Background/aim: CHARGE syndrome is a rare autosomal dominant disease with multiple congenital anomalies and cognitive impairment, which is caused by mutations in the CHD7 gene. This study aimed to disclose the mild end of the phenotypic spectrum of CHARGE syndrome, which has a highly variable expressivity. Materials and methods: Twenty-one patients who had at least one of the major symptoms of CHARGE syndrome (coloboma, choanal atresia, characteristic ear anomalies, semicircular canal hypoplasia, and cranial nerve anomalies) were included in the study. All patients were tested for karyotype analysis and CHD7 gene mutation/deletion. Results: In the study population, 6 different mutations were detected in 5 patients, and 2 different polymorphisms were detected in the CHD7 gene in 3 patients. MLPA analysis of all coding exons of the CHD7 gene revealed no pathogenic deletion/duplication. Conclusion: CHARGE syndrome should be considered as a differential diagnosis to detect the mild end of the spectrum, even if the patient does not fit the criteria.

Ring chromosome 13 is a rare genetic condition with an incidence of 1/58,000 in live births. Major clinical features of patients with ring chromosome 13 include growth and developmental retardation, microcephaly, facial dysmorphism, ambiguous genitalia, anal atresia, eye malformations, retinoblastoma, and hand, foot, and toe abnormalities. The severity of the phenotype depends on the amount of genetic material lost during ring chromosome formation. Here, we report 2 cases with ring chromosome 13 at either end of the phenotypic spectrum., (© 2018 S. Karger AG, Basel.)