Open AccessNeuropathologic Assessment of Dementia Markers in Identical and Fraternal Twins
Author(s) -
Iacono Diego,
Volkman Inga,
Nennesmo Inger,
Pedersen Nancy L.,
Fratiglioni Laura,
Johansson Boo,
Karlsson David,
Winblad Bengt,
Gatz Margaret
Publication year - 2014
Publication title -
brain pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.986
H-Index - 132
eISSN - 1750-3639
pISSN - 1015-6305
DOI - 10.1111/bpa.12127
Subject(s) - concordance , zygosity , dementia , neuropathology , monozygotic twin , twin study , disease , pathology , psychology , alzheimer's disease , medicine , biology , genetics , heritability
Twin studies are an incomparable source of investigation to shed light on genetic and non‐genetic components of neurodegenerative diseases, as Alzheimer's disease ( AD ). Detailed clinicopathologic correlations using twin longitudinal data and post‐mortem examinations are mostly missing. We describe clinical and pathologic findings of seven monozygotic ( MZ ) and dizygotic ( DZ ) twin pairs. Our findings show good agreement between clinical and pathologic diagnoses in the majority of the twin pairs, with greater neuropathologic concordance in MZ than DZ twins. Greater neuropathologic concordance was found for β ‐amyloid than tau pathology within the pairs. ApoE 4 was associated with higher β ‐amyloid and earlier dementia onset, and importantly, higher frequency of other co‐occurring brain pathologies, regardless of the zygosity. Dementia onset, dementia duration, difference between twins in age at dementia onset and at death, did not correlate with AD pathology. These clinicopathologic correlations of older identical and fraternal twins support the relevance of genetic factors in AD , but not their sufficiency to determine the pathology, and consequently the disease, even in monozygotic twins. It is the interaction among genetic and non‐genetic risks which plays a major role in influencing, or probably determining, the degeneration of those brain circuits associated with pathology and cognitive deficits in AD .