A fetus coexisting with a complete hydatidiform mole with trisomy 9 of maternal origin.

A complete hydatidiform mole (CHM) coexisting with a viable fetus is a rare finding in pregnancies. Accurate diagnosis often relies on ultrasonographic, histopathological and molecular techniques in the definite diagnosis. To the best of our knowledge, a liveborn fetus coexisting with CHM with trisomy 9 has not been described. The use of molecular genotyping and immunohistochemical laboratory investigations enabled the CHM to be fully characterized. Postzygotic diploidization of a triploid conception arising from dispermy is the proposed mechanism of its formation.

Diagnostic yield of array CGH in patients with autism spectrum disorder in Hong Kong.

BACKGROUND: Chromosomal microarray offers superior sensitivity for identification of submicroscopic copy number variants (CNV) and it is advocated to be the first tier genetic testing for patients with autism spectrum disorder (ASD). In this regard, diagnostic yield of array comparative genomic hybridization (CGH) for ASD patients is determined in a cohort of Chinese patients in Hong Kong. METHODS: A combined adult and paediatric cohort of 68 Chinese ASD patients (41 patients in adult group and 27 patients in paediatric group). The genomic DNA extracted from blood samples were analysed by array CGH using NimbleGen CGX-135K oligonucleotide array. RESULTS: We identified 15 CNV and eight of them were clinically significant. The overall diagnostic yield was 11.8 %. Five clinically significant CNV were detected in the adult group and three were in the paediatric group, providing diagnostic yields of 12.2 and 11.1 % respectively. The most frequently detected CNV was 16p13.11 duplications which were present in 4 patients (5.9 % of the cohort). CONCLUSIONS: In this study, a satisfactory diagnostic yield of array CGH was demonstrated in a Chinese ASD patient cohort which supported the clinical usefulness of array CGH as the first line testing of ASD in Hong Kong.

Maternal serum anti-Mullerian hormone level is not superior to chronological age in predicting Down syndrome pregnancies.

OBJECTIVE: To compare the difference in maternal serum anti-Mullerian hormone (AMH) level between Down syndrome pregnancies and unaffected pregnancies, and to evaluate its performance as a screening marker for Down syndrome pregnancy. METHOD: A total of 145 pregnancies affected by foetal Down syndrome and 290 unaffected controls matched with maternal age and gestational age were selected, and their archived first or second trimester serum retrieved for AMH assay. RESULTS: There was no significant difference in maternal serum AMH level between pregnancies affected and unaffected by foetal Down syndrome. Our first trimester serum samples had higher AMH concentration compared to second trimester samples. CONCLUSIONS: Maternal serum AMH level, as a marker of ovarian age, is not superior to chronological age in predicting Down syndrome pregnancies. Despite the cross-sectional nature of our study, the variation of maternal serum AMH concentration with gestational age warrants further investigation.