Validity of family history for the diagnosis of dementia among siblings of patients with late-onset Alzheimer's disease

Associations between childhood family emotional health, fronto-limbic grey matter volume, and saliva 5mC in young adulthood

Background

Poor family emotional health (FEH) during childhood is prevalent and impactful, and likely confers similar neurodevelopmental risks as other adverse social environments. Pointed FEH study efforts are underdeveloped, and the mechanisms by which poor FEH are biologically embedded are unclear. The current exploratory study examined whether variability in 5-methyl-cytosine (5mC) and fronto-limbic grey matter volume may represent pathways through which FEH may become biologically embedded.

Results

In 98 university students aged 18–22 years, retrospective self-reported childhood FEH was associated with right hemisphere hippocampus (b = 10.4, p = 0.005), left hemisphere amygdala (b = 5.3, p = 0.009), and right hemisphere amygdala (b = 5.8, p = 0.016) volumes. After pre-processing and filtering to 5mC probes correlated between saliva and brain, analyses showed that childhood FEH was associated with 49 5mC principal components (module eigengenes; MEs) (p_range = 3 × 10^–6 to 0.047). Saliva-derived 5mC MEs partially mediated the association between FEH and right hippocampal volume (Burlywood ME indirect effect b = − 111, p = 0.014), and fully mediated the FEH and right amygdala volume relationship (Pink4 ME indirect effect b = − 48, p = 0.026). Modules were enriched with probes falling in genes with immune, central nervous system (CNS), cellular development/differentiation, and metabolic functions.

Conclusions

Findings extend work highlighting neurodevelopmental variability associated with adverse social environment exposure during childhood by specifically implicating poor FEH, while informing a mechanism of biological embedding. FEH-associated epigenetic signatures could function as proxies of altered fronto-limbic grey matter volume associated with poor childhood FEH and inform further investigation into primarily affected tissues such as endocrine, immune, and CNS cell types.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-021-01056-y.

Saitohin and APOE polymorphisms influence cognition and function in persons with advanced Alzheimer Disease

BACKGROUND/AIMS

Alzheimer disease (AD) is characterized by variability in the onset and progression of cognitive, functional and behavioral symptoms. The purpose of this study was to identify genetic correlates of symptom variability in persons with moderate-to-advanced AD.

METHODS

Repeated measures of cognition, function and behavior were collected from institutionalized persons with AD over 12 months. Candidate genes were assayed.

RESULTS

Single polymorphisms within the saitohin and APOE genes were associated with increased cognitive impairment and functional dependence. The APOE-ε4 allele was associated with increased baseline physical agitation.

CONCLUSION

The development of predictive profiles for the clinical symptoms of AD may increase our ability to identify clinical subgroups for more targeted intervention.

The Influence of Informant Characteristics on the Reliability of Family History Interviews

Family history interviews are widely used in psychiatric research, as well as in genetic and twin studies, and provide a way to collect family history information quickly and economically. To obtain a valid assessment of family history, it is important to investigate which family member will be able to provide accurate information. Previous research shows that the validity of family history reporting can be influenced by characteristics of the informant, such as age, gender and personal history of psychiatric disorder. The aim of this study was to investigate the role of a subject's position in a pedigree on the validity of data collection. Family history data on diabetes and psychiatric disorders were collected in three generations of 33 families by interviewing both an index subject (3rd generation) and his or her mother (2nd generation). Mothers were shown to report higher rates of diabetes and psychiatric disorder in the family compared to the index subjects. There was no significant difference in the disease rate reported by male and female index subject. Mothers who experienced a depressive episode indicated significantly more family members as having a psychiatric disorder than mothers who never experienced such an episode. This could be explained by the presence of informant bias, but may also result from the fact that depression is a heritable disorder and is therefore actually more prevalent in these families. Our findings suggest that family interview data should be collected by interviewing subjects who have a central position in the pedigree and can therefore provide information on his/her own generation, the previous and the next. In addition, psychiatric status of the informant should be carefully addressed.

Accuracy of family history information on epilepsy and other seizure disorders

BACKGROUND

In epilepsy as in other disorders, family history information is often obtained by asking patients about the medical histories of their relatives rather than interviewing or examining the relatives directly. The accuracy of this type of information for epilepsy and other seizure disorders is unclear.

METHODS

This study used data from the Genetic Epidemiology of Seizure Disorders in Rochester study, a population-based investigation including all Rochester, MN, residents born ≥1920 with incidence of unprovoked seizures from 1935 to 1994 (case probands) and control probands matched by age, gender, and prior Rochester residency period. Seizure disorders in the first-degree relatives of case and control probands were ascertained by reviewing the relatives' medical records. Case and control probands were interviewed about seizures in their first-degree relatives using a validated 9-question screening interview. Interviewers were blinded to case-control status.

RESULTS

Sensitivity of the family history (i.e., proportion of relatives with medical record-documented seizures who screened positive in the proband interview) was 62% (32/52) for epilepsy, 50% (7/14) for isolated unprovoked seizures, and 56% (9/16) for febrile seizures. Sensitivity did not differ by case/control status of the proband. Sensitivity was much higher for probands reporting on their offspring or siblings than their parents. Among relatives with epilepsy, 90% of offspring and 80% of siblings but only 32% of parents screened positive.

CONCLUSIONS

Family histories of epilepsy are reasonably accurate for siblings and offspring, but are underreported in parents. Family histories of other seizure disorders are underreported.

Validity of family history in essential tremor

In this study, we found the sensitivity and specificity of family history data given by essential tremor (ET) patients to be 43.3% and 94.4%. Compared to relatives with less severe tremor (tremor score <24), those with more severe tremor (tremor score 24) were more likely to be identified by the ET probands (8/8 vs. 5/22, p=0.001, chi2 14.3). Our study suggests that family history information reported by ET patients was inaccurate, and poorly validated. Clinical and genetic studies in ET should take the limitation of family history data into consideration.

A multi-center, randomized, double blind placebo-controlled trial of estrogens to prevent Alzheimer's disease and loss of memory in women: design and baseline characteristics

BACKGROUND

Observational studies and small clinical trials suggested that hormone replacement therapy (HRT) decreases risk of cognitive loss and Alzheimer's disease (AD) in postmenopausal women and may have value in primary prevention.

PURPOSE

A clinical trial was designed to determine if HRT delays AD or memory loss. This report describes the rationale and original design of the trial and details extensive modifications that were required to respond to unanticipated findings that emerged from other studies during the course of the trial.

METHODS

The trial was designed as a multi-center, placebo-controlled primary prevention trial for women 65 years of age or older with a family history of dementia. Recruitment from local sites was supplemented by centralized efforts to use names of Medicare beneficiaries. Inclusion criteria included good general health and intact memory functioning. Participants were randomized to HRT or placebo in a 1:1 ratio. Assignment was stratified by hysterectomy status and site. The primary outcomes were incident AD and memory decline on neuropsychological testing.

RESULTS

Enrollment began in March 1998. In response to the Women's Health Initiative (WHI) May 2002 report of increased incidence of heart disease, stroke, pulmonary embolism, and breast cancer among women randomized to HRT, participants were re-consented with a revised consent form. Procedural modifications, including discontinuation of study medication and a modification of the planned primary outcome based on a final enrollment below the target enrollment (N = 477), were enacted in response to the subsequent WHI Memory Study report of increased risk of dementia and poorer cognitive function with HRT. The mean length of treatment exposure prior to discontinuation was 2.14 years. Participants' mean age at baseline was 72.8; mean education was 14.2 years. Minority participation was 19% and 34% had a hysterectomy. The study continues to follow these participants for a total of 5 years blind to the original medication assignment.

LIMITATIONS

Results reported from the WHI during the course of this study mandated extensive procedural modifications, including discontinuing recruitment before completion and halting study medication. Alternative strategies for study redesign that were considered are discussed.

Cancer Family History Reporting: Impact of Method and Psychosocial Factors

Family history is one the greatest risk factors for disease and one of the most important informational tools in medical genetics for the purpose of diagnosis, risk assessment, prevention and treatment. However, research is needed on the comparability of different methods of cancer family history assessment and the influence of psychosocial factors in family history reports. The purpose of this study was to determine if individuals had discrepancies between written and interview reports of cancer family history and the role of psychosocial factors in these discrepancies. Oncology patients (n=104) were administered a survey to assess psychosocial factors (i.e., information-seeking, worry, perceived risk, and health literacy) and were asked to provide family history in a written and an interview form. Randomization determined which form individuals received first. No differences in the amount of missing data or the amount of unspecified data were noted between the written and interview method. Psychosocial factors did not differentiate between those who had discrepancies in family history reports and those who did not have discrepancies in family history reports; although there was a trend for those with lower literacy and those who were blunters to be more discrepant on type of cancer diagnosis. In sum, this preliminary study indicates that written and interview methods of family history assessment for first degree relatives may be used interchangeably. The ability to use written methods will facilitate collection of basic family history information in the oncology clinic.

Familial Alzheimer disease in Latinos: interaction between APOE, stroke, and estrogen replacement

BACKGROUND

Factors that modify risk related to APOE variants have been examined primarily in unrelated patients and controls, but seldom in family-based studies. Stroke, vascular risk factors, estrogen replacement therapy (ERT), head injury (HI), and smoking have been reported to influence risk of sporadic but not familial Alzheimer disease (AD).

OBJECTIVES

To examine the potential relationship between these risk factors and APOE, the authors used a family study design in a population in which the APOE-epsilon4 variant is strongly associated with risk of AD.

METHODS

Latino families primarily from the Caribbean Islands in which two or more living relatives had dementia were identified in the New York City metropolitan area, the Dominican Republic, and Puerto Rico. A total of 1,498 participants from 350 families underwent a clinical interview, medical and neurologic examinations, neuropsychological testing, and APOE genotyping. Diagnosis was made by consensus using research criteria for AD.

RESULTS

APOE-epsilon4 was associated with a nearly twofold increased risk of AD. A history of stroke was also associated with a fourfold increased risk. A statistical interaction between APOE-epsilon4 and stroke was observed. Women with an APOE-epsilon4 who took ERT did not have an increased risk of AD, but in women with a history of stroke ERT was a deleterious effect modifier.

CONCLUSIONS

APOE-epsilon4 and stroke independently increase risk of familial Alzheimer disease (AD) among Latinos, and may interact to further increase AD risk. Among women, the risk of AD associated with APOE-epsilon4 may be attenuated by a history of ERT.

Genetic influences on life span and survival among elderly African-Americans, Caribbean Hispanics, and Caucasians

An investigation of the genetic influences on life span and survival was conducted among elderly African-Americans, Caribbean Hispanics, and Caucasians Medicare recipients (ages 65-104 years). Family history information on 13,161 parents and siblings was obtained. Heritability of life span varied by the age and by ethnic group being lowest for African-Americans. We recalculated the heritability coefficients for life span including only probands and their siblings, but the differences across ethnic groups persisted. In contrast the heritability of survival was more similar across ethnic groups but was similar to that for life span. Heritability coefficients for survival in probands and their siblings revealed little difference between ethnic groups and suggested that as much as 35% of the variation in survival may be genetically influenced. These results indicate that life span and survival are genetically influenced. Comparisons across generations and ethnic groups indicate that changes in environmental hygiene, social welfare, and health care systems are significant contributors to life span and survival, but genetic influences are also important. Identifying the genes associated with life span and survival will provide insight into how the genes interact with environment to influence aging in humans.

Influence of APOE genotype on familial aggregation of AD in an urban population

OBJECTIVE

To examine the influence of the proband's APOE genotype on AD among first-degree relatives in a community-based study of African Americans, whites, and Caribbean Hispanics.

METHODS

History of AD and demographic information were obtained on 1,073 siblings and parents of 312 patients with AD and 2,722 siblings and parents of 802 nondemented controls. APOE genotyping was performed on all 1,114 patients and controls.

RESULTS

A higher proportion of patients with AD (35%) than controls (27%) had one or more APOE-epsilon4 alleles (p = 0.03). When compared with relatives of controls without an APOE-epsilon4 allele, the risk for AD was increased in first-degree relatives of both patients (rate ratio [RR] = 1.9, 95% confidence interval [CI] = 1.2 to 3.1) and controls (RR = 1.8, 95% CI = 1.2 to 2.6) with one or more APOE-epsilone alleles, regardless of ethnic group. There was a similar trend of increased risk in relatives of patients without an APOE-epsilon4 allele, but this was limited to Hispanics and African Americans.

CONCLUSIONS

The presence of an APOE-epsilon4 allele increases risk for AD among first-degree relatives, regardless of the probands' disease status, among all ethnic groups. Relatives of patients without an APOE-epsilon4 allele were also at increased risk for AD among Hispanics and African Americans, suggesting that other genes or risk factors may influence risk.

Validity of family history data on essential tremor

BACKGROUND

In family studies of essential tremor (ET), valid data on the presence of ET in relatives of probands with ET is important. The family history method uses information obtained by interviewing probands with ET to identify ET in their relatives. The validation of this method by direct examination of the relatives has not been performed.

OBJECTIVE

To determine the validity of family history data on ET in families in which the proband has ET.

METHODS

ET cases (probands) and their respective relatives were enrolled in a genetic study of ET in Washington Heights-Inwood, New York. Each underwent a tremor interview and videotaped examination. Two neurologists rated the severity of tremor and assigned diagnoses (ET versus normal). Probands were asked to identify their relatives who had ET. The validity of the probands' responses was tested against the neurologists' diagnoses.

RESULTS

There were 206 subjects: 46 ET cases and 160 relatives. Twelve (7.5%) of 160 relatives were diagnosed with ET (four definite ET and eight probable ET). Probands with ET reported that two of these 12 had tremor (sensitivity of probands' report = 16.7%). Six of the 12 affected relatives (50.0%) reported their own tremor. The probands reported that one of 136 of their unaffected relatives had tremor (specificity of probands' report = 99.3%).

CONCLUSIONS

For family studies of ET, information on reportedly unaffected relatives is of limited use given the low sensitivity of family history data. The neurologic examination remains the only valid means of ascertaining cases of ET among relatives.

Risk of Alzheimer's disease in relatives of Parkinson's disease patients with and without dementia

OBJECTIVE

To determine whether first-degree relatives of PD patients with dementia were at increased risk for the development of AD compared with first-degree relatives of nondemented PD patients and nondemented normal subjects from the community.

METHODS

A structured family history interview was administered to 146 nondemented PD patients, 120 patients with PD and dementia, and 903 normal subjects from the community to ascertain the presence of AD among parents and siblings of these subjects. Cox proportional hazards models with double censoring techniques for missing information were used to model the risk of AD among relatives.

RESULTS

No increase in risk of AD was found among parents of patients with PD and dementia or parents of nondemented PD patients compared with parents of normal subjects. However, siblings of demented PD patients were three times as likely (relative risk [RR] = 3.2, 95% confidence interval [CI] = 1.1 to 9.4, p < 0.04) as siblings of normal subjects to develop AD. When only siblings >65 years of age were considered, there was a fivefold increase in risk of AD among siblings of demented PD patients compared with siblings of normal subjects (RR = 4.9, 95% CI = 1.1 to 21.4, p < 0.03). The risk of AD was also increased for female relatives, regardless of whether the woman was a relative of a demented PD patient, a nondemented PD patient, or a normal subject. Ethnicity and APOE genotype did not affect dementia status among relatives.

CONCLUSIONS

The increased risk of AD in siblings of demented PD patients compared with siblings of normal subjects supports the possibility of familial aggregation of AD and PD with dementia.