Researchers Recommend Genetic Testing For Some Medulloblastoma Sub-Groups

A study that looked into what genetic factors influence medulloblastoma development has been published in Lancet Oncology. In it, researchers outline several genes they believe are linked to tumour formation and suggest genetic screening guidelines. The full article discussing these findings can be found here, at CURE (Cancer Updates, Research, and Education).
Medulloblastoma is a malignant brain tumour that mainly affects children (accounting for 15-20% of all malignant childhood brain tumours) but in rare cases can also occur in adults. Medulloblastomas usually affects children between the ages of 3 to 8, and boys are slightly more at risk than girls.

There are four sub-groups of medulloblastomas. Each group is characterised by a certain typical group of symptoms, patient demographics, tumour response to therapy, and molecular profile. The groups are known as WNT, sonic hedgehog, and groups 3 and 4.

However, despite theories that some medulloblastomas are, to some extent, heritable, there is little information about which genes are likely to be responsible, and what the genetic screening guidelines are. The new study, called Spectrum and prevalence of genetic predisposition in medulloblastoma, identifies certain genes that the researchers believe are linked to medulloblastoma development and propose potential screening practices.

The study was carried out on a total of 1022 patients with medulloblastomas, 673 of the cases were retrospective (occurred in the past), and 349 were prospective (on-going cases).

Participants had their whole genome sequenced, and the researchers looked for genetic alterations that could be linked to cancer development and are inherited.

The results indicated six different genes that may predispose someone towards developing a medulloblastoma. These were APC, BRCA2, TP53, PALB2, PTCH1, and SUFU. The first three genes were also associated with an increased risk of colon, ovarian, and breast cancers, amongst others.

The researchers estimated that the six genes were linked to approximately 5% of medulloblastoma cases, although the proportions varied between subgroups. Groups 3 and 4 had estimated levels below 5%. The proportion for the sonic hedgehog subgroup was thought to be closer to 20% of cases, and for the WNT group, it was 10%.
Based on these results, the researchers advised that genetic testing and counselling should be used as a standard-of-care practice for patients that belong to the subgroups WNT and sonic hedgehog since these groups seemed to have the highest levels of genetic predisposition.

Anna Hewitt

Anna Hewitt

Anna is from England and recently finished her undergraduate degree. She has an interest in medicine and enjoys writing. In her spare time she likes to cook, hike, and hang out with cats.

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