Non-Invasive prenatal testing to determine fetal gender


Description

Free fetal DNA may be detected in maternal plasma from early in gestation and used for determination of fetal gender. Total cell-free DNA reflecting both maternal and fetal material is extracted from maternal plasma collected from 7 weeks gestation. Molecular analysis is performed using real time PCR and Taqman MGB probes for the Y-specific SRY and control-CCR5 markers. The presence of SRY marker in duplicate samples is used to indicate the presence of a male fetus and reduce false positives. In the case of detection of total cell free DNA but absence of the SRY marker, indicative of a female fetus we rely on results from repeated analysis at gestation beyond 7 weeks and the cfDNA control marker to discriminate between a true and false negative result.

Also known as

NIPD, NIPT, cffDNA, cell-free fetal DNA sex determination


Request a test

When requesting this test please use the referral form provided. Please also refer to any additional information provided for this test. Download the referral form >


Additional information

Please notify laboratory in advance of sending a sample, samples should arrive within 48 hours. Gestation as determined by ultrasound scan is mandatory information to perform this test. This test is not applicable before 7 weeks gestation or in multiple pregnancies including vanishing twin. Testing is only offered to females at risk of having a child with a severe X-linked disorder. Download additional information >


Sending address

Great Ormond Street Hospital NE Thames Regional Genetics Service Laboratories
Great Ormond Street Hospital for Children
Barclay House
37 Queen Square
London
WC1N 3BH

Laboratory service

Genetics


Sample requirements

20ml blood (EDTA) from mother. Post 9 weeks this can be obtained in one sampling. At 7-9 weeks gestation 2 x 10ml sample should be taken one week apart.


Reference range

Not applicable


Turnaround time

3 days from receipt of second sample


Disease / group

SRY


Cost

Upon request


Call in advance?

All referrals should be made via a Clinical Genetics Department, please contact the laboratory in advance of sending a sample.� Advance notice is required so samples can be processed rapidly upon receipt


Genetics

The Genetics Laboratories provide an extensive range of Cytogenetics and Molecular Genetics diagnostic testing services...

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