Molar Pregnancy, 16 DNA Markers
0051755
 
Ordering Recommendation
Diagnose complete or partial molar pregnancy.
Mnemonic
MOL PREG
Methodology
Polymerase Chain Reaction/Fragment Analysis
Performed
Mon-Fri
Reported
Within 14 days
New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
 
Collect
Products of conception.  
Specimen Preparation
Formalin fix and paraffin embed tissue containing areas of villi and of decidua. In some cases, decidua may not be present in sufficient amounts, and a maternal blood sample may be requested. Transport tissue block.  
Storage/Transport Temperature
Room temperature. Ship in a cooled container during the summer months.  
Unacceptable Conditions
Paraffin block with no tissue remaining. Specimens fixed in formalin substitute.  
Remarks
Include surgical pathology report.  
Stability
Ambient: Indefinitely; Refrigerated: Indefinitely; Frozen: Unacceptable  
Reference Interval
Interpretive Data
Background information for Molar Pregnancy, 16 DNA Markers:
Characteristics of Complete Mole:
Typically presents with vaginal bleeding and ultrasound showing enlarged placenta, marked trophoblastic hyperplasia and swollen villi. If diagnosed in the first trimester, embryonic tissue may be present; by the second trimester, no fetal tissue is evident.
Characteristics of Partial Mole:
Typically presents as a threatened or missed abortion at the end of the first trimester; if still viable in the second trimester, a large placenta with hydropic change of some villi and a growth restricted fetus is usually observed.
Incidence of Complete and Partial Moles:
Approximately 1 in 1500 and 1 in 700 pregnancies respectively, with regional and ethnic variation observed.
Inheritance:
The majority of cases are de novo; rare recurrences may be due to heritable mutations.
Cause of Complete Mole:
Typically due to doubling of chromosome content of a normal 23,X sperm fertilizing an egg lacking a maternal set of chromosomes; occasionally results from two sperm fertilizing an egg lacking maternal chromosomes; karyotype is 46,N.
Cause of Partial Mole:
Typically due to a normal ovum fertilized by two sperm resulting in a 69,XXX or 69,XXY chromosome complement.
Clinical Sensitivity:
Estimated to be 99 percent.
Clinical Specificity:
Greater than 99 percent.
Methodology:
PCR followed by capillary electrophoresis. Specimens are analyzed using 15 short tandem repeat (STR) markers (D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, vWa, TPOX, D18S51, D5S818 and FGA) and one gender marker (amelogenin).
Analytical sensitivity and specificity:
99 percent.
Limitations:
Contamination of villi / decidua may occur. Inhibitors present in the specimen can interfere with the polymerase chain reaction. Rare case of heritable molar pregnancy may appear normal by STR analysis. Diagnostic errors can occur due to rare sequence variations.

See Compliance Statement B: www.aruplab.com/CS
Note
CPT Code(s)
81265; 88381
Components
Component Test Code*Component Chart Name
0051757Molar Pregnancy, 16 DNA Markers
2001366MOL PREG Specimen
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, contact interface support at interface.support@aruplab.com.
Cross References