PALB2

Molecular test PALB2 gene 

PALB2 (Partner And Localizer Of BRCA2) encodes a protein that may function in tumor suppression. This protein binds to and colocalizes with BRCA2 in nuclear foci and likely permits the stable intranuclear localization and accumulation of BRCA2. Serves as the molecular scaffold in the formation of the BRCA1-PALB2-BRCA2 complex which is essential for homologous recombination.

Antoniou et al. (2014) analyzed the risk of breast cancer among 362 members of 154 families who had deleterious truncating, splice, or deletion mutations in PALB2. They estimated cumulative risk of breast cancer among female mutation carriers was 14% (95% confidence interval, 9 to 20) by 50 years of age and 35%) by 70 years of age, but it can reach up to 58% if at least two first degree family members are affected by the tumor.

However, the role of PALB2 related to increased risk for ovarian cancer has not yet been clarified.

For those women (or men) who did not find mutations in BRCA1 and BRCA2 genes, it is advisable to extend genetic analysis to the PALB2 gene. Especially in families where there are many cases of breast cancer and pancreatic cancer.

In positive women with PALB2 mutations, breast intensive surveillance or preventive surgery is recommended.

Jones et al. (2009) concluded that PALB2 appears to be the second most commonly mutated gene for hereditary pancreatic cancer. The most commonly mutated gene is BRCA2, whose protein product is a binding partner for the PALB2 protein.

 Inheriting two abnormal PALB2 genes causes Fanconi anemia type N, which suppresses bone marrow function and leads to extremely low levels of red blood cells, white blood cells, and platelets. People with Fanconi anemia also have a higher risk of several other types of cancer, including kidney cancer and brain cancer.

 

The test is performed on NGS platform in 7 working days starting from a blood sample (2 EDTA tubes).

 

References:

NCCN Guidelines Version 1.2017 – Genetic/Familial High-Risk Assesment: Breast and Ovarian

Antoniou AC, et al. Breast-cancer risk in families with mutations in PALB2. N Engl J Med. 2014 Aug 7;371(6):497-506. doi: 10.1056/NEJMoa1400382.

Kanchi KL, et al. Integrated analysis of germline and somatic variants in ovarian cancer. Nat Commun. 2014;5:3156. doi: 10.1038/ncomms4156.

Norquist BM, et al. Inherited Mutations in Women With Ovarian Carcinoma. JAMA Oncol. 2016 Apr;2(4):482-90. doi: 10.1001/jamaoncol.2015.5495.