SNP-based Microdeletion and Aneuploidy RegisTry (SMART) (SMART)
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ClinicalTrials.gov Identifier: NCT02381457 |
Recruitment Status :
Completed
First Posted : March 6, 2015
Last Update Posted : January 29, 2021
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Condition or disease |
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22q11 Deletion Syndrome DiGeorge Syndrome Trisomy 21 Trisomy 18 Trisomy 13 Monosomy X Sex Chromosome Abnormalities Cri-du-Chat Syndrome Angelman Syndrome Prader-Willi Syndrome 1p36 Deletion Syndrome |
The primary objective is to determine in a prospective study the performance of SNP based NIPT for the 22q11.2 microdeletion (DiGeorge syndrome) in a large cohort of pregnant women clinically opting for this form of screening. Specific test performance parameters will include: positive predictive value (PPV), specificity, and sensitivity.
Secondary objectives include:
- Determine the test performance (PPV, specificity) of SNP based NIPT for detecting other microdeletion syndromes available in the Panorama microdeletion panel (e.g., 1p36 deletion, Cri-du-chat, Prader-Willi, and Angelman) individually and all combined (including 22q11.2). Given the incidences of <1:5000, the confidence intervals are expected to be large.
- Determine the failure ('no call') rate for the Next-generation Aneuploidy Test Using SNPs (NATUS) method for 22q11.2 detection, as well as for aneuploidy.
- Determine whether a more precise risk for aneuploidy can be generated in the setting of low fetal fraction by incorporating maternal BMI (adjusted fetal fraction percentile).
- Assess whether low fetal fraction is associated with specific ultrasound findings that may indicate aneuploidy (e.g. triploidy, trisomy 13 and 18).
- Investigate the relationship between NIPT and sonographic (nuchal translucency and anatomy survey) markers and serum markers from 1st and 2nd trimester aneuploidy screening.
- Determine sensitivity, specificity, and PPV for chromosomal aneuploidies and sex chromosome abnormalities.
- Perform detailed assessment of false positive aneuploidy samples to better understand sources of error, including placental studies to further refine issues surrounding mosaicism as NIPT represents circulating placental DNA.
- Investigate any relationships between circulating placental DNA (fetal fraction) or other test parameters including potential genotypic markers, and outcomes related to abnormal placentation (including but not limited to preeclampsia, small for gestational age and morbidly adherent placenta).
- Investigate other risk factors that may impact risk assessment for microdeletions including sonographic findings consistent with 22q11.2 (cardiac anomalies and thymus size).
Study Type : | Observational [Patient Registry] |
Actual Enrollment : | 20960 participants |
Observational Model: | Cohort |
Time Perspective: | Prospective |
Target Follow-Up Duration: | 2 Years |
Official Title: | SNP-based Microdeletion and Aneuploidy RegisTry |
Actual Study Start Date : | April 2015 |
Actual Primary Completion Date : | June 2020 |
Actual Study Completion Date : | June 2020 |

Group/Cohort |
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Pregnancies undergoing prenatal microdeletion screening
Pregnant women undergoing non-invasive prenatal screening for microdeletion and aneuploidy syndromes. No drug will be administrated, this cohort will undergo a non invasive prenatal blood test and then follow up data and specimens will be collected for research analysis. |
- 22q11.2 Snp-based non-invasive prenatal screening test performance, including positive predictive value (PPV), specificity, and sensitivity [ Time Frame: 3 years ]To determine in a prospective study the performance of SNP based NIPT for the 22q11.2 microdeletion (DiGeorge syndrome) in a large cohort of pregnant women clinically opting for this form of screening.
- Combined microdeletion syndrome screening test performance [ Time Frame: 3 years ]Determine the test performance (PPV, specificity) of SNP based NIPT for detecting other microdeletion syndromes available in the Panorama microdeletion panel (e.g., 1p36 deletion, Cri-du-chat, Prader-Willi, and Angelman) individually and all combined (including 22q11.2). Given the incidences of <1:5000, the confidence intervals are expected to be large.
- No call rate [ Time Frame: 3 years ]Determine the failure ('no call') rate for the NATUS method for 22q11.2 detection, as well as for aneuploidy.
- Low fetal fraction aneuploidy risk refinement [ Time Frame: 3 years ]Determine whether a more precise risk for aneuploidy can be generated in the setting of low fetal fraction by incorporating maternal BMI (adjusted fetal fraction percentile), or whether low fetal fraction is associated with specific ultrasound findings that may indicate aneuploidy (e.g. triploidy, trisomy 13 and 18).
- Placental mosaicism exploration [ Time Frame: 3 years ]Perform detailed assessment of false positive aneuploidy samples to better understand sources of error, including placental studies to further refine issues surrounding mosaicism as NIPT represents circulating placental DNA.
- Placental complications exploration [ Time Frame: 3 years ]Investigate any relationships between circulating placental DNA (fetal fraction) or other test parameters including potential genotypic markers, and outcomes related to abnormal placentation (including but not limited to preeclampsia, small for gestational age and morbidly adherent placenta).
Biospecimen Retention: Samples With DNA
- Maternal residual blood sample
- Placental tissue
- Child dried blood spot
- Child buccal sample

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Ages Eligible for Study: | 18 Years to 48 Years (Adult) |
Sexes Eligible for Study: | Female |
Accepts Healthy Volunteers: | Yes |
Sampling Method: | Non-Probability Sample |
Inclusion Criteria:
- Singleton pregnancy
- Receiving Panorama prenatal screening test for both microdeletions (at least 22q11.2) and aneuploidy
- Planned hospital delivery
- Gestational age of ≥ 9 weeks, 0 days based on clinical information and evaluation.
- Able to provide informed consent
Exclusion Criteria:
- Received results of the Panorama test prior to enrollment
- Organ transplant recipient
- Egg donor used

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02381457

Principal Investigator: | Peer Dar, MD | Montefiore Medical Center | |
Principal Investigator: | Mary Norton, MD | University of California, San Francisco |
Publications of Results:
Other Publications:
Responsible Party: | Natera, Inc. |
ClinicalTrials.gov Identifier: | NCT02381457 |
Other Study ID Numbers: |
14-024-NPT |
First Posted: | March 6, 2015 Key Record Dates |
Last Update Posted: | January 29, 2021 |
Last Verified: | January 2021 |
Microdeletion Syndrome Aneuploidy 22q Non-Invasive Prenatal Screening DiGeorge Syndrome |
DiGeorge Syndrome 22q11 Deletion Syndrome Prader-Willi Syndrome Down Syndrome Angelman Syndrome Trisomy 13 Syndrome Cri-du-Chat Syndrome Trisomy 18 Syndrome Chromosome Disorders Syndrome Aneuploidy Trisomy Chromosome Aberrations Monosomy Sex Chromosome Aberrations |
Disease Pathologic Processes Congenital Abnormalities Intellectual Disability Neurobehavioral Manifestations Neurologic Manifestations Nervous System Diseases Abnormalities, Multiple Genetic Diseases, Inborn Obesity Overnutrition Nutrition Disorders Chromosome Duplication Movement Disorders Central Nervous System Diseases |