1/4. A family with a grand-maternally derived interstitial duplication of proximal 15q.About 1% of individuals with autism or types of pervasive developmental disorder have a duplication of the 15q11-q13 region. These abnormalities can be detected by routine G-banded chromosome study, showing an extra marker chromosome, or demonstrated by fluorescence in situ hybridization (FISH) analysis, revealing an interstitial duplication. We report here the molecular, cytogenetic, clinical and neuropsychiatric evaluations of a family in whom 3 of 4 siblings inherited an interstitial duplication of 15q11-q13. This duplication was inherited from their mother who also had a maternally derived duplication. Affected family members had apraxia of speech, phonological awareness deficits, developmental language disorder, dyslexia, as well as limb apraxia but did not have any dysmorphic clinical features. The observations in this family suggest that the phenotypic manifestations of proximal 15q duplications may also involve language-based learning disabilities.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
2/4. Characterization of the first supernumerary tricentric ring chromosome 1 mosaicism by conventional and molecular cytogenetic techniques.We report on the conventional cytogenetic and fluorescence in situ hybridization (FISH) results obtained for a 3.5-year-old girl with developmental and language delay and a supernumerary ring chromosome mosaicism in 8% of t-lymphocytes analyzed. Using different conventional and molecular cytogenetic techniques as YAC hybridization and comparative genomic hybridization, we could show that the extra tricentric ring chromosome consists of three heterochromatic blocks with inserted euchromatic material. Additionally, chromosome microdissection followed by FISH analysis demonstrated that the small tricentric ring chromosome consisted of material from the pericentromeric region of chromosome 1q21. Thus, the patient has a mosaic of normal cells and cells with partial pentasomy of the pericentromeric region of chromosome 1. So far, 19 cases with single supernumerary marker chromosome 1 have been published, but no tricentric ring chromosome 1 is, to our knowledge, reviewed in the literature. In this study, we compare the clinical features of our patient with cytogenetically comparable cases described in the literature. We introduce a hypothesis for the formation of a tricentric ring chromosome: starting with a monocentric ring, sister chromatid exchange leading to the formation of a tetracentric ring, which underwent intrastrand recombination generating the tricentric ring.- - - - - - - - - - ranking = 3keywords = hybridization (Clic here for more details about this article) |
3/4. 22q13 deletion syndrome with central diabetes insipidus: a previously unreported association.We describe a two-year-old girl with 22q13 deletion syndrome (MIM # 606232), 46, XX, de l (22) (q13.31). ish del (22) (q13.31) (TUPLE 1 ,ARSA-). The patient has hypotonia, normal growth, severe expressive language delay, mild mental retardation, and minor dysmorphic facial features. In addition, she had central diabetes insipidus that was diagnosed at age two days and resolved at age 27 months. To our knowledge, this association has not been reported previously. Infants with hypotonia, or those suspected to have this syndrome should have high-resolution chromosome analysis and fluorescent in situ hybridization (FISH) studies or molecular analysis, since the chromosomal deletion may be subtle and may go undetected on routine cytogenetic studies. The association of 22q13 deletion syndrome with central diabetes insipidus is reported for the first time.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
4/4. An unusual case of monosomy 18p: minor malformations with speech delay.An unusual case of monosomy 18p with molecular cytogenetic characterization of 18;21 whole arm translocation who had mild speech delay and normal motor development is presented. A 3.5-year-old boy with complaints of speech delay, open mouth and drooling saliva was the child of a 33-year-old healthy mother and 35-year-old nonconsangineous father with unremarkable prenatal history. Beside delayed speech, hyperactive movements, flat nasal bridge, prominent ears, micrognathia, hypotonia, and overriding of left 3rd the on 2nd toe were present. Cytogenetic studies revealed de novo 45,XY del (18) t(18;21)-21 karyotype, which was confirmed by fluorescence in situ hybridization (FISH).- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |