Jacobsen syndrome detected by noninvasive prenatal testing.

BACKGROUND: Noninvasive prenatal testing has a high detection rate of common fetal chromosomal aneuploidies. However, detection of additional chromosome abnormalities has not been well described or validated. CASE: We report a case of Jacobsen syndrome, a congenital disorder involving deletion of chromosome 11q, detected by noninvasive prenatal testing at 14 weeks of gestation and confirmed on neonatal testing with array chromosomal genomic hybridization. CONCLUSION: Noninvasive prenatal testing should be considered when multiple fetal anomalies are present and invasive testing is declined. As the clinical application of noninvasive prenatal testing continues to evolve, additional submicroscopic chromosomal information may be clinically helpful and should be confirmed with diagnostic testing until larger studies help further define the screening characteristics of noninvasive prenatal testing.

Chromosomal microarray analysis and prenatal diagnosis.

Chromosomal microarray analysis (CMA) assesses chromosomal copy number alterations and affords higher resolution when compared with standard karyotype. This review provides the obstetric provider with an update on the technology, use, and controversies concerning CMA utilization in prenatal diagnosis. Chromosomal microarray analysis offers increased resolution for copy number abnormalities compared with traditional karyotype. There is high-quality evidence for the added detection of clinically significant copy number alterations with CMA in prenatal diagnosis when the traditional karyotype is normal. Other potential advantages of CMA include a quicker turnaround time and utilization in clinical situations with a high probability of nondividing cells (ie, intrauterine fetal demise, spontaneous miscarriage, and third-trimester amniocentesis). Chromosomal microarray analysis may be beneficial when prenatally detected structural anomalies are associated with specific microdeletions and microduplications or to assess for copy number variants when a de novo balanced rearrangement or marker chromosome is diagnosed. Use of CMA includes the detection of copy number variants of uncertain significance. In light of these issues, large prospective cohort studies are needed to illustrate the diagnostic utility of CMA for detection of prenatal chromosomal abnormalities in low-risk populations before routine clinical use of CMA is recommended in all circumstances of prenatal diagnosis.

Practice guidelines for communicating a prenatal or postnatal diagnosis of Down syndrome: recommendations of the national society of genetic counselors.

Down syndrome is one of the most common conditions encountered in the genetics clinic. Due to improvements in healthcare, educational opportunities, and community inclusion over the past 30 years, the life expectancy and quality of life for individuals with Down syndrome have significantly improved. As prenatal screening and diagnostic techniques have become more enhanced and widely available, genetic counselors can expect to frequently provide information and support following a new diagnosis of Down syndrome. This guideline was written for genetic counselors and other healthcare providers regarding the communication of a diagnosis of Down syndrome to ensure that families are consistently given up-to-date and balanced information about the condition, delivered in a supportive and respectful manner.