RESUMO
BACKGROUND: The bladder exstrophy-epispadias complex (BEEC) represents the severe end of the congenital uro-rectal malformation spectrum. Initial studies have implicated rare copy number variations (CNVs), including recurrent duplications of chromosomal region 22q11.21, in BEEC etiology. METHODS: To detect further CNVs, array analysis was performed in 169 BEEC patients. Prior to inclusion, 22q11.21 duplications were excluded using multiplex ligation-dependent probe amplification. RESULTS: Following the application of stringent filter criteria, seven rare CNVs were identified: n = 4, not present in 1307 in-house controls; n = 3, frequency of <0.002 in controls. These CNVs ranged from 1 to 6.08 Mb in size. To identify smaller CNVs, relaxed filter criteria used in the detection of previously reported BEEC associated chromosomal regions were applied. This resulted in the identification of six additional rare CNVs: n = 4, not present in 1307 in-house controls; n = 2, frequency <0.0008 in controls. These CNVs ranged from 0.03-0.08 Mb in size. For 10 of these 13 CNVs, confirmation and segregation analyses were performed (5 of maternal origin; 5 of paternal origin). Interestingly, one female with classic bladder extrophy carried a 1.18 Mb duplication of 22q11.1, a chromosomal region that is associated with cat eye syndrome. CONCLUSIONS: A number of rare CNVs were identified in BEEC patients, and these represent candidates for further evaluation. Rare inherited CNVs may constitute modifiers of, or contributors to, multifactorial BEEC phenotypes.
Assuntos
Extrofia Vesical/genética , Análise Citogenética/métodos , Variações do Número de Cópias de DNA , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Aneuploidia , Transtornos Cromossômicos/genética , Duplicação Cromossômica , Cromossomos Humanos Par 22/genética , Anormalidades do Olho/genética , Feminino , Humanos , Masculino , Herança Materna , Herança PaternaRESUMO
BACKGROUND: Bladder exstrophy is a rare malformation. Prenatal diagnosis is usually an incidental finding on routine ultrasound examination. Triple-X syndrome (karyotype 47,XXX) is the most frequent sex chromosome aneuploidy in live-born females (approximately 1 in 1000). The diagnosis is often not made because women with 47,XXX karyotype have no or hardly any clinical symptoms during life. METHODS: Prenatal diagnosis of triple X karyotype is usually an incidental finding when an invasive prenatal diagnosis is performed for other reasons. RESULTS: Here, we report on two cases with bladder exstrophy and triple-X syndrome, one in a fetus and one in an adult. In view of two previous reports of this association in literature, causality of these two conditions should be considered. CONCLUSION: A gene dosage effect as possible underlying mechanisms will be discussed.
Assuntos
Extrofia Vesical/genética , Epispadia/genética , Dosagem de Genes/genética , Transtornos do Cromossomo Sexual no Desenvolvimento Sexual/genética , Trissomia/genética , Adulto , Extrofia Vesical/diagnóstico por imagem , Extrofia Vesical/etiologia , Cromossomos Humanos X/genética , Epispadia/diagnóstico por imagem , Epispadia/etiologia , Evolução Fatal , Feminino , Feto , Humanos , Hibridização in Situ Fluorescente , Cariotipagem , Aberrações dos Cromossomos Sexuais , Transtornos do Cromossomo Sexual no Desenvolvimento Sexual/complicações , UltrassonografiaRESUMO
BACKGROUND: Classic bladder exstrophy (CBE) is the most common form of the bladder exstrophy and epispadias complex. Previously, we and others have identified four patients with a duplication of 22q11.21 among a total of 96 unrelated CBE patients. METHODS: Here, we investigated whether this chromosomal aberration was commonly associated with CBE/bladder exstrophy and epispadias complex in an extended case-control sample. Multiplex ligation-dependent probe amplification and microarray-based analysis were used to identify 22q11.21 duplications in 244 unrelated bladder exstrophy and epispadias complex patients (including 217 CBE patients) and 665 healthy controls. RESULTS: New duplications of variable size were identified in four CBE patients and one control. Pooling of our previous and present data (eight duplications in 313 CBE patients) yielded a combined odds ratio of 31.86 (95% confidence interval, 4.24-1407.97). Array-based sequence capture and high-throughput targeted re-sequencing established that all breakpoints resided within the low-copy repeats 22A to 22D. Comparison of the eight duplications revealed a 414 kb phenocritical region harboring 12 validated RefSeq genes. Characterization of these 12 candidate genes through whole-mount in situ hybridization of mouse embryos at embryonic day 9.5 suggested that CRKL, THAP7, and LZTR1 are CBE candidate genes. CONCLUSION: Our data suggest that duplication of 22q11.21 increases CBE risk and implicate a phenocritical region in disease formation.
