A unique demographic history exists for the MAO-A gene in Polynesians

Abstract

Variation in the human monoamine oxidase A (MAO-A) gene can influence neurotransmittor levels and is thought to have a role in many behavioral traits. The genetic architecture of MAO-A is known to vary across different geographic subgroups. Previous studies have reported evidence for positive selection within the MAO-A gene region in seven ethnic groups: Pygmy, Aboriginal Taiwanese, Chinese, Japanese, Mexican and Russian. Polynesian populations have not been tested and repeated founder effects due to the island-hopping voyages of Polynesians across the South Pacific suggest a unique demographic history exists at the MAO-A gene, perhaps including selective effects. To explore this, we genotyped 13 key single-nucleotide polymorphisms (SNPs) spanning MAO-A gene as well as the functional polymorphism (MAO-A-uVNTR) in 47 unrelated Maori individuals. A comparison of genetic variation between Maori and non-Maori groups found a substantial reduction in genetic diversity at the MAO-A gene locus and an increase in the frequency of the most common MAO-A gene variant in the Maori group. Results of this study support previous findings and also point toward a 5-SNP haplotype that may have been influenced by selective effects in the Maori population. Full-sequence data for MAO-A in a large cohort are now required to conclusively determine whether MAO-A has undergone positive selection in Polynesians. Overall, these new data describe a unique demographic history for the MAO-A gene in the Maori population and will be helpful for studies wishing to investigate MAO-A as a candidate gene for influencing behavioral traits in the Polynesians.

Next‐generation sequencing targeted disease panel in rod‐cone retinal dystrophies in Māori and Polynesian reveals novel changes and a common founder mutation

“…From Eastern Polynesia, the New Zealand Māori migrated to New Zealand around 750 years ago and represent a relatively new population genetically (about 35 generations). In the migration through the Pacific, it has been hypothesized that the ancestors would likely have been subject to multiple founder effects and consistent with this, reduced genetic diversity, and small numbers of haplotypes have been demonstrated in other studies …”

“…In the migration through the Pacific, it has been hypothesized that the ancestors would likely have been subject to multiple founder effects and consistent with this, reduced genetic diversity, and small numbers of haplotypes have been demonstrated in other studies. 22 Eastern Polynesians are thought to have descended from Taiwan Aborigines with subsequent mixing with European and Melanesian. 23,24 Of Polynesians, the Māori have the smallest signal of external relationship, consistent with extensive genetic drift.…”

MAOA variants differ in oscillatory EEG & ECG activities in response to aggression-inducing stimuli

“…Pathological aggression related to antisociality or violence is highly heritable 1–5 , and previous work estimated that genetic factors account for approximately 50% of the variation in aggression 6 . Among candidate genes for aggression, mutations, deletions, single-nucleotide polymorphisms (SNPs), and variable number of tandem repeats (VNTRs) in the X-linked monoamine oxidase A ( MAOA ) gene were the first known genetic deficiencies in animal and human models 7–9 . The gene product monoamine oxidase A, which is expressed in specific cells of the human brain and peripheral tissues 10–12 , metabolizes monoamines, such as the neurotransmitters serotonin, norepinephrine, and dopamine, which are involved in the regulation of emotions 13–15 .…”