Genetic Counseling Dilemmas for a Patient with Sporadic Amyotrophic Lateral Sclerosis, Frontotemporal Degeneration & Parkinson's Disease

Abstract

Amyotrophic lateral sclerosis (ALS), frontotemporal degeneration and Parkinson's disease may be different expressions of the same neurodegenerative disease. However, association between ALS and parkinsonism-dementia complex (ALS-PDC) has only rarely been reported apart from the cluster detected in Guam. We report a patient presenting with ALS-PDC in whom pathological mutations/expansions were investigated. No other family members were reported to have any symptoms of a neurological condition. Our case demonstrates that ALS-PDC can occur as a sporadic disorder, even though the coexistence of the three clinical features in one patient suggests a single underlying genetic cause. It is known that genetic testing should be preferentially offered to patients with ALS who have affected first or second-degree relatives. However, this case illustrates the importance of genetic counseling for family members of patients with sporadic ALC-PDC in order to provide education on the low recurrence risk. Here, we dicuss the ethical, psychological and practical consequences for patients and their relatives.

Patient and Relative Experiences and Decision-making About Genetic Testing and Counseling for Familial ALS and FTD

“…The included population consisted of affected individuals, at-risk individuals, and other related or unrelated family members. Eleven studies included only a single person or family with, or at risk of, ALS/FTD 38–41,46,49–51,56–58. The total number of included patients, families and at-risk relatives was not calculated due to missing information or differences in defining familial and sporadic disease.…”

“…Given the possible familial impacts of diagnostic testing, due to both familial risks and progressive disease, a family-centered approach is supported 41,53,56,58,59. While relatives may become responsible for making time-dependent decisions about testing or communicating results in other LONDs,60 fALS/fFTD genetic testing may be further complicated by certain disease characteristics.…”

“…Eleven studies included only a single person or family with, or at risk of, ALS/FTD. [38][39][40][41]46,[49][50][51][56][57][58] The total number of included patients, families and at-risk relatives was not calculated due to missing information or differences in defining familial and sporadic disease.…”

“…Eight ALS, 6,11,12,28,31,32,36,[38][39][40][41] 4 FTD 49,[51][52][53] and 4 ALS-FTD [55][56][57][58] studies reported experiences of diagnostic testing. In 1 national survey from the United States, most of the 105 ALS patients who underwent diagnostic testing were positive about their experience and satisfied with the pretest discussion, explanation of results and implications, and emotional support provided, 6,11,12 and indicated the results were useful to them and their families.…”

“…Study authors deemed some diagnostic testing experiences as problematic for patients or relatives in studies across the United States, UK, Australia and Italy. Issues arose with FTD patients' capacity to consent 53,58 or ALS patients' communication abilities 41 due to disease progression. Some relatives became responsible for consenting to genetic testing on the patient's behalf 41,53,56,58 and notifying relatives about a genetic finding.…”