Diamond-Blackfan Anemia (DBA) is characterized by a defect of erythroid progenitors and, clinically, by anemia and malformations. DBA exhibits an autosomal dominant pattern of inheritance with incomplete penetrance. Currently nine genes, all encoding ribosomal proteins (RP), have been found mutated in approximately 50% of patients. Experimental evidence supports the hypothesis that DBA is primarily the result of defective ribosome synthesis. By means of a large collaboration among six centers, we report here a mutation update that includes nine genes and 220 distinct mutations, 56 of which are new. The DBA Mutation Database now includes data from 355 patients. Of those where inheritance has been examined, 125 patients carry a de novo mutation and 72 an inherited mutation. Mutagenesis may be ascribed to slippage in 65.5% of indels, whereas CpG dinucleotides are involved in 23% of transitions. Using bioinformatic tools we show that gene conversion mechanism is not common in RP genes mutagenesis, notwithstanding the abundance of RP pseudogenes. Genotype–phenotype analysis reveals that malformations are more frequently associated with mutations in RPL5 and RPL11 than in the other genes. All currently reported DBA mutations together with their functional and clinical data are included in the DBA Mutation Database.

Sex chromosome aneuploidy was frequently suspected on NIPT. False positive rate for monosomy X was surprisingly high (91%). Prediction of other SCA was more accurate. Diagnostic fetal chromosome analysis should be offered after abnormal NIPT or in the presence of cystic hygromas despite normal NIPT. NIPT limitations should be explained in pretest counseling. © 2017 John Wiley & Sons, Ltd.

Objective Evaluate patient choices and outcomes following positive cfDNA.Method Retrospective cohort study of women with positive cfDNA through two academic centers between March 2012 and December 2014. Patients were screened based on ACOG indications. Medical records reviewed for counseling, ultrasound findings, diagnostic testing, karyotype and outcome.Results CfDNA was positive in 114 women; 105 singletons and 9 twin pairs. CfDNA was positive for autosomal trisomy (21, 18, 13) in 96 (84.2%) and sex chromosome aneuploidy in 18 (15.8%). Certified genetic counselors performed 95% of post-cfDNA counseling. Prenatal diagnostic testing was pursued by 71/114 (62%). Karyotype was available in 91/105 (86.7%) singletons and confirmed aneuploidy in 75/91 (82.4%); the PPV of cfDNA with any ultrasound finding was 93.6% versus 58.6% without a finding. An abnormal sonographic finding was seen in 4/16 (25%) singletons with false positive cfDNA. Fetal termination occurred in 53/79 (67%) singletons and 3/5 (60%) twins with prenatal abnormal or unknown karyotype for autosomal trisomy. Eleven fetuses (11/56, 19.6%) were terminated for suspected autosomal trisomy without karyotype confirmation.Conclusion Patient choices following positive cfDNA are varied. Ultrasound modifies the PPV of cfDNA. Termination rates for aneuploidy are not higher than historical controls. Recommendation for karyotype confirmation prior to termination is not universally followed.

Objective This study aimed to examine the role of the 11-to 14-week ultrasound in women with negative cell-free DNA screening.Methods A retrospective cohort study of women at increased risk for aneuploidy based on age or medical history and negative cell-free DNA screening between March 2012 and March 2014 was conducted. Patients were included if they had an 11-to 14-week ultrasound and obstetrical care at our center(s). Primary outcome was an unexpected finding at ultrasound. Imaging findings were compared with obstetrical outcome by medical record review.Results Study group was composed of 1739 patients. An unexpected finding was identified in 60/1739 (3.5%). An abnormal fetal finding occurred in 37 living fetuses (2.1%); 33 had a nuchal translucency (NT) ≥ 3 mm, including four 'isolated' cystic hygroma and three with a structural abnormality. Four fetuses had a structural anomaly without a thick NT. Karyotype confirmed euploidy in 98.7% of available cases. Pregnancy termination was chosen by 63.6% of those with cystic hygroma or anomaly at the 11-to 14-week scan. Unexpected multiples were identified in 13 (0.7%) women and a fetal demise in 10 (0.6%).Conclusion Unexpected findings at the 11-to 14-week scan occur in 3.5% of patients with negative cell-free DNA.Recognition provides options for comprehensive testing, consultation, and management.

When a sacrococcygeal extension is seen on fetal imaging, work-up should include detailed fetal imaging and karyotype, and fetal growth should be monitored. Our experience with fetal sacrococcygeal extension demonstrates variability in the underlying presentation and etiology, making counseling in a prenatal setting challenging.