Indications For Patau syndrome (trisomy 13)
Patau syndrome, also known as trisomy 13, is a syndrome in which a patient has an additional chromosome 13,
Patau syndrome symptoms include:

Mental & motor retardation
Polydactyly (extra digits)
Holoprosencephaly (failure of the forebrain to divide properly).
Heart defects
Structural eye defects, including microphthalmia, Peters anomaly, cataract, iris and/or fundus (coloboma), retinal dysplasia or retinal detachment, sensory nystagmus, cortical visual loss, and optic nerve hypoplasia
Meningomyelocele (a spinal defect)
Omphalocele (abdominal defect)
Abnormal genitalia
Abnormal palm pattern
Overlapping of fingers over thumb.
Cutis aplasia (missing portion of the skin/hair)
Prominent heel
Microcephaly
Low-set ears
Cleft palate or hare lip

Collection Procedure
•    Amniotic fluid
Discard the first 2 cc of fluid to reduce the risk of maternal cell contamination.  Aseptically transfer 15-20 cc into sterile plastic conical tubes labeled with patient’s name and date of birth.
•    CVS
Aseptically transfer 5-10mg into sterile plastic conical tubes containing sterile transport medium.  Label tube with patient’s name and date of birth.
•    Peripheral blood
Collect 5-10 cc whole blood in a green top tube (sodium heparin).  Label tube with patient’s name and date of birth.
A completed test requisition form must be included with every sample.  A transport kit is available upon request.

Specimen Requirements
Labortory testing for Patau syndrome testing can be performed as a SAT 24 hour FISH study on interphase cells followed by complete cytogenetic analysis (karyotype)

Transport Temperature

Room temperature (DO NOT refrigerate, freeze or centrifuge)

Methodology

24-hour laboratory testing for Patau Syndrome (trisomy 13) can be performed by Fluorescence in situ hybridization on interphase nuclei followed by confirmatory cytogenetic analysis.

Causes for Rejection

Frozen specimen, inappropriate container

Turnaround Time

FISH: 24 hours
Cytogenetic analysis: 7-10 days