Clinical and genetic patterns of neurological diseases other than amyotrophic lateral sclerosis on Guam

An Unusual Combination of Mirror-Image Dextrocardia with Familial Medulloblastoma: Is There a Histogenetic Relationship?

BACKGROUND

The occurrence of medulloblastoma in the absence of hereditary syndromes is rare. Dextrocardia with situs inversus is also called mirror-image dextrocardia. A combination of mirror-image dextrocardia with medulloblastoma has not been reported previously. To the best of our knowledge, this is the first report of this rare combination in a family with medulloblastoma.

METHODS

The clinical manifestation, radiographic characteristics, treatment, and outcomes of 3 medulloblastoma cases in 2 cousins and their maternal uncle was described. Tumor samples of the 2 cousins were first examined for histologic subtypes. Total RNA of their tumors was extracted from formalin-fixed and paraffin-embedded samples. Then, expression of 22 subgroup-specific genes and 3 housekeeping genes was analyzed by the NanoString nCounter Analysis System. The posttest data were normalized by NanoStringNorm package for molecular subgroup prediction.

RESULTS

The proband remains tumor free and alive up to the latest follow-up. His cousin, who had combined mirror-image dextrocardia with situs inversus, died of anoxia after surgery and his uncle died of tumor 2.5 years after surgery. Medulloblastoma of the 2 cousins was classified as classic and molecular group 4 subtype.

CONCLUSIONS

The same classic and molecular group 4 subtype of the 2 cousins may suggest a similar genetic predisposition. Involvement of the Otx2 gene dysfunction in both group 4 subtype medulloblastoma and mirror-image dextrocardia with situs inversus points to a possible mechanism that dysfunction of a shared signaling pathway such as Otx2 might be the underlying cause of these 2 conditions in this family.

Familial medulloblastoma: case report of one family and review of the literature

OBJECTIVE AND IMPORTANCE

Medulloblastoma is the most common malignant brain tumor and the most common malignant solid tumor in children. Most medulloblastomas are sporadic, but rare familial forms have been described. To the best of our knowledge, only 10 case reports of familial medulloblastoma have been published. A variety of candidate genes have been suggested to be involved in familial medulloblastomas. However, the exact pathogenesis and genetics involved in familial medulloblastoma remain unknown.

CLINICAL PRESENTATION

We describe the presentation of medulloblastoma in two siblings (one of each sex) and their great-uncle. The three cases differ with regard to age at onset and pathological subtype of medulloblastoma. INTERVENTION OR TECHNIQUE: Immunostaining of tissue blocks for gene products involved in medulloblastoma differed in the two siblings for beta-catenin and was similar with staining for gli.

CONCLUSION

This article is only the second report in the literature to address the genetics of familial medulloblastoma in the absence of characterized conditions such as Li-Fraumeni's cancer syndrome and basal cell nevus, Rubinstein-Taybi's, and Turcot's syndromes. The discrepancy in beta-catenin staining in the two siblings suggests that the two tumors differentiated through divergent pathways. We briefly summarize all published cases of familial medulloblastoma and review the literature on the genes involved in medulloblastoma formation.

Glioblastoma multiforme in four siblings: a cytogenetic and molecular genetic study

The familial occurrence of gliomas, in the absence of well-defined neurological tumor syndromes such as the neurofibromatoses, is uncommon. We present a family of ten children in which the four eldest suffered from gliomas. Three of these siblings had histologically verified glioblastoma multiforme, and one patient also had an intestinal non-Hodgkin's lymphoma, but there were no stigmata or family history of a neurological tumor syndrome. Cytogenetic studies of the proband revealed a normal karyotype. Molecular genetic analysis of the proband's glioblastoma revealed two mutations in the p53 tumor suppressor gene, but these were not present in the germline DNA, mutations were not detected in the MTS1 gene in the tumors or in the germline DNA. These findings suggest that a genetic factor may be responsible for the clustering of glial tumors in this family, but it is unlikely that the genetic alteration is mutation of the p53 gene. The data are discussed in light of the literature on familial brain tumors.

Familial medulloblastoma in siblings: report in one family and review of the literature

Two siblings in a family--a 5-year-old boy and an 8-year-old girl--suffered from progressive headache and gait disturbance in an interval of 1 year, consecutively. Neurologic manifestations were papilledema and truncal ataxia. Both of their computed tomography scans showed a large, well-enhanced tumor located in the cerebellar vermis with secondary hydrocephalus. Both had surgical resection followed by craniospinal irradiation and then chemotherapy. The pathologic findings confirmed the diagnosis of medulloblastomas. The family pedigree disclosed some other cancer in close relatives. These findings suggested a possible role of heredity in the oncogenesis of this tumor. To our knowledge, our cases are the seventh report of familial medulloblastoma occurring in nontwin siblings in the world.