1/5. Three probands with autistic disorder and isodicentric chromosome 15.We have identified three unrelated probands with autistic disorder (AD) and isodicentric chromosomes that encompass the proximal region of 15q11.2. All three probands met the diagnostic and statistical manual of mental disorders, fourth edition [DSM-IV; American Psychiatric association, 1994], and international classification of diseases ( ICD-10) diagnostic criteria for AD, confirmed with the Autism Diagnostic interview -Revised (ADI-R). Chromosome analysis revealed the following karyotypes: 47,XX, idic(15)(q11.2), 47,XX, idic(15) (q11.2), and 47,XY, idic(15)(q11.2). Haplotype analysis of genotypic maker data in the probands and their parents showed that marker chromosomes in all three instances were of maternal origin. Comparison of the clinical findings of the three AD probands with case reports in the published literature (N = 20) reveals a clustering of physical and developmental features. Specifically, these three probands and the majority of reported probands in the literature exhibited hypotonia (n = 13), seizures (n = 13), and delayed gross motor development (n = 13). In addition, clustering of the following clinical signs was seen with respect to exhibited speech delay (n = 13), lack of social reciprocity (n = 11), and stereotyped behaviors (n = 12). Collectively, these data provide further evidence for the involvement of chromosome 15 in AD as well as present preliminary data suggesting a clustering of clinical features in AD probands with proximal 15q anomalies.- - - - - - - - - - ranking = 1keywords = physical (Clic here for more details about this article) |
2/5. Isolated congenital anonychia cases with coincident chromosomal fragility.Isolated anonychia without any associated phenotypical disturbances is one of the rarest anomalies of congenital nail disorders. Some or all fingers of the hands or feet could be affected. Anonychia can be encountered in dermatologic disorders like pemphigus, lichen planus, epidermolysis bullosa; it can also be seen as a component of some syndromes like Nail-patella and Cooks syndromes. We present a sister couple in whom all fingernails and toenails were lacking without any additional physical sign. A fragile chromosomal site was also encountered in peripheral chromosome analysis in the long arm of the chromosome 10 in both of the cases.- - - - - - - - - - ranking = 1keywords = physical (Clic here for more details about this article) |
3/5. A BrdU-requiring fragile site on chromosome 12.A BrdU-requiring fragile site, fra(12)(q24.2), on human chromosome 12 of some individuals is reported. This fragile site is inherited in a Mendelian codominant fashion and does not seem to be associated with any physical or mental abnormality in carriers. It was mostly observed as a chromatid gap: no acentric fragments, triradials or deleted chromosomes were found. The fra(12)(q24.2) was expressed in 34%-48% of metaphases in lymphocyte cultures from carriers when BrdU and FdU were added 6.5 h before harvest, while the expression ranged between 5% and 20% when the cultures were treated with BrdU alone. The fra(12)(q24.2) represents the second BrdU-requiring rare fragile site described on human chromosomes.- - - - - - - - - - ranking = 1keywords = physical (Clic here for more details about this article) |
4/5. Fra(2) (q13) and inv(9) (p11q12) in autism: causal relationship?Twenty individuals with autism or related disorders underwent chromosome analysis and physical examinations with documentation of minor anomalies. Chromosome anomalies were identified in 3: 2 had the heritable folate sensitive fra(2) (q13) site and 1 had an inv(9) (p11q12). No heritable chromosome variants or anomalies were seen in 20 age and sex-matched control individuals. When patients with the fra(2) were excluded from analyses, there was no difference in the frequency of chromosome breaks and/or gaps between the study group and control group. The results of this study suggest that heritable folate sensitive fragile sites and other chromosome variants may be more commonly seen in individuals with autism or related disorders in childhood than in the general population.- - - - - - - - - - ranking = 1keywords = physical (Clic here for more details about this article) |
5/5. Physical localisation of the breakpoints of a constitutional translocation t(5;6)(q21;q21) in a child with bilateral Wilms' tumour.A 6 month old boy presented with bilateral Wilms' tumour. cytogenetic analysis of the lymphocytes from the patient showed a de novo balanced translocation t(5;6)(q21;q21), which was also present in the tumour material as the sole cytogenetic abnormality. To facilitate the identification of the translocation breakpoints, we have established a lymphoblastoid cell line (MA214L) from the patient which maintains the translocation in culture. We have used Genethon microsatellite markers as sequence tagged sites (STSs) to isolate yeast artificial chromosome (YAC) clones to 5q and 6q from human genomic libraries. Using fluorescence in situ hybridisation (FISH) on metaphase preparations of MA214L, we have physically defined the translocation breakpoints between YAC clones on each chromosome arm. The genetic distance separating the flanking YACs on 6q21 is 3 cM, while that on 5q21 is 4 cM. To date this is the first report of these chromosomal regions being implicated in Wilms' tumourigenesis.- - - - - - - - - - ranking = 1keywords = physical (Clic here for more details about this article) |