RESUMEN
OBJECTIVE: To verify whether fluorescence in situ hybridization (FISH) of cells from the buccal epithelium could be employed to detect cryptomosaicism with a 45,X lineage in 46,XY patients. SUBJECTS AND METHODS: Samples of nineteen 46,XY healthy young men and five patients with disorders of sex development (DSD), four 45,X/46,XY and one 46,XY were used. FISH analysis with X and Y specific probes on interphase nuclei from blood lymphocytes and buccal epithelium were analyzed to investigate the proportion of nuclei containing only the signal of the X chromosome. RESULTS: The frequency of nuclei containing only the X signal in the two tissues of healthy men did not differ (p = 0.69). In all patients with DSD this frequency was significantly higher, and there was no difference between the two tissues (p = 0.38), either. CONCLUSIONS: Investigation of mosaicism with a 45,X cell line in patients with 46,XY DSD or sterility can be done by FISH directly using cells from the buccal epithelium.
Asunto(s)
Trastornos del Desarrollo Sexual/genética , Trastornos del Desarrollo Sexual/patología , Hibridación Fluorescente in Situ , Mosaicismo , Mucosa Bucal , Adolescente , Adulto , Núcleo Celular , Niño , Preescolar , Trastornos del Desarrollo Sexual/sangre , Femenino , Disgenesia Gonadal 46 XY/sangre , Disgenesia Gonadal 46 XY/genética , Disgenesia Gonadal Mixta/sangre , Disgenesia Gonadal Mixta/genética , Humanos , Infertilidad Masculina/genética , Interfase , Linfocitos , Masculino , Síndrome de Turner/genética , Adulto JovenRESUMEN
Objetivo: Verificar se a hibridização in situ por fluorescência (FISH) em células de mucosa oral poderia ser empregada para detectar criptomosaicismo com linhagem 45,X em pacientes 46,XY. Sujeitos e métodos: Amostra de 19 jovens saudáveis 46,XY e cinco pacientes com distúrbios da diferenciação do sexo (DDS), quatro 45,X/46,XY e um 46,XY. FISH com sondas específicas para X e Y em núcleos interfásicos de linfócitos e mucosa oral para investigar a proporção de núcleos contendo apenas o sinal do cromossomo X. Resultados: A frequência de núcleos contendo apenas o sinal do X nos dois tecidos dos homens saudáveis não diferiu (p = 0,69). Em todos os pacientes com DDS essa frequência foi significativamente maior, e também não houve diferença entre os dois tecidos (p = 0,38). Conclusões: A investigação de mosaicismo com linhagem 45,X em pacientes com DDS 46,XY ou esterilidade pode ser feita por FISH diretamente em células de mucosa oral. .
Objective: To verify whether fluorescence in situ hybridization (FISH) of cells from the buccal epithelium could be employed to detect cryptomosaicism with a 45,X lineage in 46,XY patients. Subjects and methods: Samples of nineteen 46,XY healthy young men and five patients with disorders of sex development (DSD), four 45,X/46,XY and one 46,XY were used. FISH analysis with X and Y specific probes on interphase nuclei from blood lymphocytes and buccal epithelium were analyzed to investigate the proportion of nuclei containing only the signal of the X chromosome. Results: The frequency of nuclei containing only the X signal in the two tissues of healthy men did not differ (p = 0.69). In all patients with DSD this frequency was significantly higher, and there was no difference between the two tissues (p = 0.38), either. Conclusions: Investigation of mosaicism with a 45,X cell line in patients with 46,XY DSD or sterility can be done by FISH directly using cells from the buccal epithelium. .
Asunto(s)
Adolescente , Adulto , Niño , Preescolar , Femenino , Humanos , Masculino , Adulto Joven , Trastornos del Desarrollo Sexual/genética , Trastornos del Desarrollo Sexual/patología , Hibridación Fluorescente in Situ , Mosaicismo , Mucosa Bucal , Núcleo Celular , Trastornos del Desarrollo Sexual/sangre , /sangre , /genética , Disgenesia Gonadal Mixta/sangre , Disgenesia Gonadal Mixta/genética , Interfase , Infertilidad Masculina/genética , Linfocitos , Síndrome de Turner/genéticaRESUMEN
FISH has been used as a complement to classical cytogenetics in the detection of mosaicism in sex chromosome anomalies. The aim of this study is to describe three cases in which the final diagnosis could only be achieved by FISH. Case 1 was an 8-year-old 46,XY girl with normal female genitalia referred to our service because of short stature. FISH analysis of lymphocytes with probes for the X and Y centromeres identified a 45,X/46,X,idic(Y) constitution, and established the diagnosis of Turner syndrome. Case 2 was a 21-month-old 46,XY boy with genital ambiguity (penile hypospadias, right testis, and left streak gonad). FISH analysis of lymphocytes and buccal smear identified a 45,X/46,XY karyotype, leading to diagnosis of mixed gonadal dysgenesis. Case 3 was a 47,XYY 19-year-old boy with delayed neuromotor development, learning disabilities, psychological problems, tall stature, small testes, elevated gonadotropins, and azoospermia. FISH analysis of lymphocytes and buccal smear identified a 47,XYY/48,XXYY constitution. Cases 1 and 2 illustrate the phenotypic variability of the 45,X/46,XY mosaicism, and the importance of detection of the 45,X cell line for proper management and follow-up. In case 3, abnormal gonadal function could be explained by the 48,XXYY cell line. The use of FISH in clinical practice is particularly relevant when classical cytogenetic analysis yields normal or uncertain results in patients with features of sex chromosome aneuploidy.
