To provide clinical details and long-term outcome data for a series of patients with eyelid or conjunctival melanoma or eyelid sebaceous cell carcinoma who underwent sentinel lymph node (SLN) biopsy. Design: Retrospective interventional case series with review of clinical records and pathologic specimens. Setting: Tertiary comprehensive cancer center. Patients: Twenty-five consecutive patients treated at 1 institution for eyelid or conjunctival melanoma or eyelid sebaceous cell carcinoma from December 2000 to October 2004. Interventions: Surgical removal of the eyelid or conjunctival tumor and SLN biopsy. Main Outcome Measures: Local treatment modalities; lymphatic basins in which SLNs were identified; status of SLNs; false-negative rate; and long-term patterns of local recurrence, regional and distant metastasis, and survival. Results: Seven patients had conjunctival melanoma, 8 had eyelid-margin melanoma with a considerable palpebral conjunctival component, and 10 had eyelid sebaceous cell carcinoma. The SLNs were identified in all but 1 patient by using technetium Tc 99m sulfur colloid as a tracer. Intraoperatively, in 16 patients in whom blue dye was used in addition to technetium Tc 99m sulfur colloid during mapping, no SLN was blue. One patient with conjunctival melanoma and 1 patient with eyelid melanoma had a histologically positive SLN. Two patients with eyelid melanoma and 2 patients with eyelid sebaceous cell carcinoma had negative findings from SLN biopsy but developed recurrence in their regional lymph nodes during the follow-up period. Overall, during followup, 2 of 10 patients with sebaceous cell carcinoma (20%) and 5 of 15 patients with eyelid or conjunctival melanoma (33%) had regional lymph node metastasis. Four patients with melanoma who had regional metastasis also developed distant organ metastasis. Two patients with sebaceous cell carcinoma-1 with regional metastasis and 1 without-developed distant organ metastasis. Conclusions: The detection of histologically positive SLNs in this series of patients may justify further study of SLN biopsy for high-risk patients with ocular adnexal melanoma or eyelid sebaceous cell carcinoma. The false-negative rate is higher than that reported for SLN biopsy at most other anatomic sites. Patients with negative findings from SLN biopsy still require careful longterm follow-up because they may develop regional or distant metastasis.

Background: The relationship between the apolipoprotein E (ApoE) genotype and the risk for developing Alzheimer’s disease (AD) or age at onset of AD is relatively well established in Caucasians, but less established in other ethnicities. We examined the association between the ApoE genotype and age at onset of AD in a quadriethnic group of community-dwelling AD patients. Methods: AD patients were evaluated at 2 university-based outpatient memory disorder clinics. The ethnic distribution was as follows: Caucasians (n = 1,083), Hispanics (n = 55), African Americans (n = 84) and Koreans (n = 87). All were diagnosed with probable AD according to NINCDS-ADRDA diagnostic criteria. Results: After adjusting for ethnicity, the Ε4 allele was significantly associated with earlier age at onset (p < 0.0001) for the combined group. Within ethnic groups, the effect of Apo Ε4 on age at onset was significant in Caucasians (p < 0.0001) and African Americans (p < 0.05), but nonsignificant in Koreans (p = 0.43) and in the smaller Hispanic (p = 0.07) group. Conclusions: The association between Apo Ε4 and younger age at onset was significant in Caucasians and African Americans, where the Ε4 allele was also most frequent. This study suggests that the impact of ApoE polymorphism on age at onset of AD may be different among distinct ethnic groups.

Limited ancestral diversity has impaired our ability to detect risk variants more prevalent in non-European ancestry groups in genome-wide association studies (GWAS). We constructed and analyzed a multi-ancestry GWAS dataset in the Alzheimer Disease (AD) Genetics Consortium (ADGC) to test for novel shared and ancestry-specific AD susceptibility loci and evaluate underlying genetic architecture in 37,382 non-Hispanic White (NHW), 6,728 African American, 8,899 Hispanic (HIS), and 3,232 East Asian individuals, performing within-ancestry fixed-effects meta-analysis followed by a cross-ancestry random-effects meta-analysis. We identified 13 loci with cross-ancestry associations including known loci at/near CR1, BIN1, TREM2, CD2AP, PTK2B, CLU, SHARPIN, MS4A6A, PICALM, ABCA7, APOE and two novel loci not previously reported at 11p12 (LRRC4C) and 12q24.13 (LHX5-AS1). Reflecting the power of diverse ancestry in GWAS, we observed the SHARPIN locus using 7.1% the sample size of the original discovering single-ancestry GWAS (n=788,989). We additionally identified three GWS ancestry-specific loci at/near (PTPRK (P=2.4E10-8) and GRB14 (P=1.7E10-8) in HIS), and KIAA0825 (P=2.9E10-8 in NHW). Pathway analysis implicated multiple amyloid regulation pathways (strongest with Padjusted=1.6E10-4) and the classical complement pathway (Padjusted=1.3E10-3). Genes at/near our novel loci have known roles in neuronal development (LRRC4C, LHX5-AS1, and PTPRK) and insulin receptor activity regulation (GRB14). These findings provide compelling support for using traditionally-underrepresented populations for gene discovery, even with smaller sample sizes.

ImportanceSex differences are established in associations between apolipoprotein E (APOE) ε4 and cognitive impairment in Alzheimer disease (AD). However, it is unclear whether sex-specific cognitive consequences of APOE are consistent across races and extend to the APOE ε2 allele.ObjectiveTo investigate whether sex and race modify APOE ε4 and ε2 associations with cognition.Design, Setting, and ParticipantsThis genetic association study included longitudinal cognitive data from 4 AD and cognitive aging cohorts. Participants were older than 60 years and self-identified as non-Hispanic White or non-Hispanic Black (hereafter, White and Black). Data were previously collected across multiple US locations from 1994 to 2018. Secondary analyses began December 2021 and ended September 2022.Main Outcomes and MeasuresHarmonized composite scores for memory, executive function, and language were generated using psychometric approaches. Linear regression assessed interactions between APOE ε4 or APOE ε2 and sex on baseline cognitive scores, while linear mixed-effect models assessed interactions on cognitive trajectories. The intersectional effect of race was modeled using an APOE × sex × race interaction term, assessing whether APOE × sex interactions differed by race. Models were adjusted for age at baseline and corrected for multiple comparisons.ResultsOf 32 427 participants who met inclusion criteria, there were 19 007 females (59%), 4453 Black individuals (14%), and 27 974 White individuals (86%); the mean (SD) age at baseline was 74 years (7.9). At baseline, 6048 individuals (19%) had AD, 4398 (14%) were APOE ε2 carriers, and 12 538 (38%) were APOE ε4 carriers. Participants missing APOE status were excluded (n = 9266). For APOE ε4, a robust sex interaction was observed on baseline memory (β = −0.071, SE = 0.014; P = 9.6 × 10−7), whereby the APOE ε4 negative effect was stronger in females compared with males and did not significantly differ among races. Contrastingly, despite the large sample size, no APOE ε2 × sex interactions on cognition were observed among all participants. When testing for intersectional effects of sex, APOE ε2, and race, an interaction was revealed on baseline executive function among individuals who were cognitively unimpaired (β = −0.165, SE = 0.066; P = .01), whereby the APOE ε2 protective effect was female-specific among White individuals but male-specific among Black individuals.Conclusions and RelevanceIn this study, while race did not modify sex differences in APOE ε4, the APOE ε2 protective effect could vary by race and sex. Although female sex enhanced ε4-associated risk, there was no comparable sex difference in ε2, suggesting biological pathways underlying ε4-associated risk are distinct from ε2 and likely intersect with age-related changes in sex biology.

Limbic-predominant age-related TDP-43 encephalopathy (LATE) affects approximately one-third of older individuals and is associated with cognitive impairment. However, there is a highly incomplete understanding of the genetic determinants of LATE neuropathologic changes (LATE-NC) in diverse populations. The defining neuropathologic feature of LATE-NC is TDP-43 proteinopathy, often with comorbid hippocampal sclerosis (HS). In terms of genetic risk factors, LATE-NC and/or HS are associated with single nucleotide variants (SNVs) in 3 genes—TMEM106B (rs1990622), GRN (rs5848), and ABCC9 (rs1914361 and rs701478). We evaluated these 3 genes in convenience samples of individuals of African ancestry. The allele frequencies of the LATE-associated alleles were significantly different between persons of primarily African (versus European) ancestry: In persons of African ancestry, the risk-associated alleles for TMEM106B and ABCC9 were less frequent, whereas the risk allele in GRN was more frequent. We performed an exploratory analysis of data from African-American subjects processed by the Alzheimer’s Disease Genomics Consortium, with a subset of African-American participants (n = 166) having corroborating neuropathologic data through the National Alzheimer’s Coordinating Center (NACC). In this limited-size sample, the ABCC9/rs1914361 SNV was associated with HS pathology. More work is required concerning the genetic factors influencing non-Alzheimer disease pathology such as LATE-NC in diverse cohorts.