ABSTRACT
Considering genetic influence on brain structure and function, including motor control, we report a case of right-handed monozygotic twins with atypical organization of fine motor movement control that might imply genetic influence. Structural and functional organization of the twins' motor function was assessed using transcranial magnetic stimulation (TMS), fMRI with a motor-task paradigm, and diffusion tensor imaging (DTI) tractography. TMS revealed that both twins presented the same unexpected activation and inhibition of both motor cortices during volitional unilateral fine hand movement. The right ipsilateral corticospinal tract was weaker than the left contralateral one. The motor-task fMRI identified activation in the left primary motor cortex and bilateral secondary motor areas during right-hand (dominant) movement and activation in the bilateral primary motor cortex and secondary motor areas during left-hand movement. Based on DTI tractography, both twins showed a significantly lower streamline count (number of fibers) in the right corticospinal tract compared with a control group, which was not the case for the left corticospinal tract. Neither twin reported any difficulty in conducting fine motor movements during their activities of daily living. The combination of TMS and advanced neuroimaging techniques identified an atypical motor control organization that might be influenced by genetic factors. This combination emphasizes that activation of the unilateral uncrossed pyramidal tract represents an alternative scheme to a "failure" of building a standard pattern but may not necessarily lead to disability.
Subject(s)
Functional Laterality/genetics , Neuroimaging/methods , Neurophysiology/methods , Adult , Humans , Male , Twins, MonozygoticABSTRACT
Thirteen STRs loci have been typed in a sample from Greece.
Subject(s)
Gene Frequency , Genetics, Population , Tandem Repeat Sequences , DNA Fingerprinting/methods , Greece , HumansABSTRACT
Haplotype, allele frequencies and population data of nine Y-chromosome STR loci, DYS385I, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, were determined from a sample of 69 unrelated Greek male individuals.
Subject(s)
Chromosomes, Human, Y/genetics , Genetics, Population , Tandem Repeat Sequences/genetics , DNA Fingerprinting , Gene Frequency , Greece , Haplotypes , Humans , Male , Polymerase Chain ReactionABSTRACT
Allele frequencies for the nine STRs included in the AmpFlSTR Profiler Plus kit (D3S1358, VWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317 and D7S820) were estimated from a sample of 143 unrelated individuals living in different regions of Greece.
