There is a high association of ASD in VI or HI children and therefore these populations should be assessed for ASD in the presence of a visual or hearing disability.

The genetic prehistory of human populations in Central America is largely unexplored leaving an important gap in our knowledge of the global expansion of humans. We report genome-wide ancient DNA data for a transect of twenty individuals from two Belize rock-shelters dating between 9,600-3,700 calibrated radiocarbon years before present (cal. BP). The oldest individuals (9,600-7,300 cal. BP) descend from an Early Holocene Native American lineage with only distant relatedness to present-day Mesoamericans, including Mayan-speaking populations. After ~5,600 cal. BP a previously unknown human dispersal from the south made a major demographic impact on the region, contributing more than 50% of the ancestry of all later individuals. This new ancestry derived from a source related to present-day Chibchan speakers living from Costa Rica to Colombia. Its arrival corresponds to the first clear evidence for forest clearing and maize horticulture in what later became the Maya region.

The (hu)MANid program is a free, web-based software using mandibular metric and morphoscopic variables to estimate sex and ancestry. The database consists of 1,745 individuals from 15 populations (modern, historic, and prehistoric). The required use of a mandibulometer presents two limitations. It is an expensive piece of equipment not available in all labs, and many users do not have experience using a mandibulometer, so error can be high. To address this, three-dimensional surface scans (3D scans) provide an alternative method for data collection. Here, the authors assess the accuracy of the (hu)MANid program on a diverse sample, compare accuracy from 3D scans and physical measurements, and evaluate whether mandibulometer measurements increase classification rates. Six metric and morphoscopic variables were collected from 3D scans (Ntotal = 555) and from bone (Ntotal = 41). Three additional mandibulometer measurements were collected from bone. Mixture discriminant analysis and non-stepwise options were applied due to reported higher correct classification and no significant difference when using stepwise options. Test samples with matching reference groups from the digital measurements had higher than chance average correct classifications for ancestry and sex/ancestry combined. Pooled sexes had correct classifications higher than chance for all comparisons except females using digital measurements. Physical measurements had a higher correct classification rate than digital measurements despite the small sample size. Including mandibulometer measurements did not significantly increase classification rates for physical measurements. Results indicate that hu(MAN)id is better than chance but suggest additional testing due to a lack of diversity in the physical measurements.

Ketogenic diets are emerging as protective interventions in preclinical and clinical models of somatosensory nervous system disorders. Additionally, dysregulation of succinyl-CoA 3-oxoacid CoA-transferase 1 (SCOT, encoded by Oxct1), the fate-committing enzyme in mitochondrial ketolysis, has recently been described in Friedreich's ataxia and amyotrophic lateral sclerosis. However, the contribution of ketone metabolism in the normal development and function of the somatosensory nervous system remains poorly characterized. We generated sensory neuron-specific, Advillin-Cre knockout of Oxct1 (SNACKO) mice and characterized the structure and function of their somatosensory system. We used histological techniques to assess sensory neuronal populations, myelination, and innervation of the skin and spinal dorsal horn. We also examined cutaneous and proprioceptive sensory behaviors with the von Frey test, radiant heat assay, rotarod, and grid-walk tests. SNACKO mice exhibited myelination deficits, altered morphology of putative Aδ soma from the dorsal root ganglion, reduced cutaneous innervation, and abnormal innervation of the spinal dorsal horn compared to wildtype mice. Synapsin 1-Cre-driven knockout of Oxct1 confirmed deficits in epidermal innervation following a loss of ketone oxidation. Loss of peripheral axonal ketolysis was further associated with proprioceptive deficits, yet SNACKO mice did not exhibit drastically altered cutaneous mechanical and thermal thresholds. Knockout of Oxct1 in peripheral sensory neurons resulted in histological abnormalities and severe proprioceptive deficits in mice. We conclude that ketone metabolism is essential for the development of the somatosensory nervous system. These findings also suggest that decreased ketone oxidation in the somatosensory nervous system may explain the neurological symptoms of Friedreich's ataxia.

No abstract