N Simon Thomas

..In these two families the translocation is most likely to have arisen from a single ancestral event because all translocation carriers shared almost identical haplotypes around the breakpoints on both chromosomes...

..This represents a unique molecular condition for LMD: the fetus is a compound heterozygote with two independent deletions, one inherited and one arising from a de novo event...

..Several factors are likely to be involved in the formation of recurrent rearrangements and the relative importance of these appear to be locus-specific...

..Presumably the lack of selection against most inversions allows them to accumulate and disperse amongst different populations over time...

..However, like the t(4;11)(p16.2;p15.4), such translocations are likely to be rare with the t(11;22) remaining the only common recurrent constitutional reciprocal translocation...

..SHOX duplications are likely to be under ascertained and more cases need to be identified and characterized in detail in order to accurately determine their phenotypic consequences...

..Methods: The parental origin of a series of de novo balanced reciprocal translocations was determined using DNA from flow sorted derivative chromosomes and linkage analysis...

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..Thus, there is a clear propensity for structural chromosome abnormalities to occur in male germ cells, although the chromosomal origin seems similar irrespective of the parental origin...

..Our data suggest that mitotic mechanisms could be important for the formation of chromosome imbalances; however, we found no association with increased paternal age...

..As a result, published cases of transmitted imbalances have been collected as a guide to the possible significance of such findings in the future (see the 'Chromosome Anomaly Collection' at www.som.soton.ac.uk/research/geneticsdiv)...

..5 years and Patient 2 showed breast development in infancy. Both patients shared some dysmorphological features, namely short palpebral fissures, a prominent nasal tip, a short philtrum and 5th finger clinodactyly...

..This report highlights the importance of parental genotyping in order to give accurate genetic counseling for autosomal recessive disorders...

..We show that the thrombocytic activity of MAOB is proportionate to the number of X-chromosomes, and hypothesize that haploinsufficiency of this enzyme in 45,X females predisposes to their deficits in social cognition...

..To perform a genotype-phenotype correlation study in an X-linked congenital idiopathic nystagmus pedigree (pedigree 1) and to assess the allelic variance of the FRMD7 gene in congenital idiopathic nystagmus...

..Thus, although considered a common variant, inv(10)(p11.2q21.2) has a single ancestral founder among northern Europeans...

..Deletion analysis of this newly identified region should be included in the mutation screening of patients with LWD, LMD, and ISS...

..They also suggest that there may be cognitive differences between the groups in processing visuo-spatial information...

..The frequency of abnormalities of 15q11-q13 and other possibly causal medical disorders including karyotypic abnormalities was investigated in an unselected series of children who were referred to one of two autism assessment centres...

..We have also narrowed the putative critical interval for X-linked spina bifida...

..These genes may therefore play a role in the aetiology of autism. By contrast with another report, there was no clear-cut relationship between the size of the deletion and the form of cognitive and behavioural phenotype...