What Can We Learn From the Co-occurrence of a Genetic Disorder and Cancer?

In a new paper in the European Journal of Medical Genetics, researchers from Nationwide Children’s Hospital discuss the case of a 4-year-old with both a rare genetic disorder and medulloblastoma. Genetic analyses allowed them to evaluate the cause of the genetic disorder and provided support for the role of the mutated gene in tumor suppression.

“We are using new technologies in the diagnosis of brain tumors that may shed some light on genetic changes of which we were not previously aware,” says Mohamed AbdelBaki, MD, a pediatric neuro-oncologist at Nationwide Children’s and one of the study’s authors. “We have seen that molecular biology and genetic sequencing help in identifying correlations between brain tumors and some genetic syndromes.”

Dr. AbdelBaki and his colleagues describe a patient with Klippel-Feil syndrome, a rare congenital bone disorder, who was then diagnosed with medulloblastoma, a common malignant brain tumor. The patient was found to harbor a mutation in the gene MYO18B.

“MYO18B was recently described as a rare genetic cause of Klippel-Feil syndrome, and it is reported to be a tumor suppressor in multiple adult solid tumors,” says Kathleen Schieffer, PhD, a postdoctoral fellow at the Steve and Cindy Rasmussen Institute for Genomic Medicine at Nationwide Children’s and the study’s lead author. “Since malignant brain tumors are not associated with Klippel-Feil syndrome, the co-occurrence of medulloblastoma was of interest, given the putative role of MYO18B as a tumor suppressor.”

Through genetic analyses, the co-existing genetic disorder and cancer diagnoses in this patient allowed the researchers to elucidate the genetic causes of Klippel-Feil syndrome and expand understanding of the development of the disease. Their findings also provide further support for the role of MYO18B in tumor suppression.

“What is truly important – and unique to our institution – is the close relationship we have with the Institute for Genomic Medicine,” says Dr. AbdelBaki, who is also assistant professor of pediatrics at The Ohio State University College of Medicine. “Their technologies and expertise help us incorporate molecular biology into our understanding of these tumors, from diagnosis to development of targeted therapies.”

“Genetic variation should be considered when evaluating pediatric tumors in the setting of precision medicine,” agrees Dr. Schieffer. “In some cases, somatic mutations within the same biological pathway as the genetic disorder may implicate targeted therapeutic management. While in other cases, identifying underlying cancer predisposition may alter surveillance or help us better understand tumor development and growth.”

Reference:

Schieffer KM, Varga E, Miller KE, Agarwal V, Koboldt DC, Brennan P, Kelly B, Dave-Wala A, Pierson CR, Finlay JL, AbdelBaki MS, White P, Magrini V, Wilson RK, Mardis ER, and Cottrell CE. Expanding the clinical history associated with syndromic Klippel-Feil: A unique case of comorbidity with medulloblastoma. European Journal of Medical Genetics. 2019 Aug 6;62(8)103701.