1: Rev Neurol 2003 Feb;36 Suppl 1:S132-7
[Williams syndrome. A summary of cognitive, electrophysiological, anatomofunctional, microanatomical and genetic findings]
[Article in Spanish]
Galaburda AM, Holinger D, Mills D, Reiss A, Korenberg JR, Bellugi U.
Beth Israel Deaconess Medical Center, Boston, MA, EE.UU.
Williams syndrome (WS) is the result of a hemideletion of about 17 genes in the q11.22 23 region of chromosome 7. Patients with WS show unique phenotypic features that include elfin face, heart malformations, calcium metabolism problems and learning disorders. The latter consist of mental retardation that is characterised by serious difficulties with processing visuospatial tasks, a striking ability to easily recognise faces, a relatively developed linguistic capacity and sensitiveness to sound, a strong need to establish affective ties with other people and a fondness for music. Anatomical studies show a decrease in the postero dorsal parts of both hemispheres of the brain, malformation in the central dorsal region and an expansion of the superior temporal gyrus, of the amygdala and of the frontal lobe. These macroscopic anomalies are accompanied by microscopic anomalies, which consist of changes in the number and size of the neurons. Studies on evoked potentials show acoustic hyperexcitability and abnormal waves related to language and to faces. Genetic studies in our laboratories show that the exact size of the deletion can vary, which means partial cases also exist and have partial phenotypes. Combining behavioural, electrophysiological, anatomical and genetic reports suggests a problem with the posterior dorsal region of the brain, possibly resulting from mistakes in establishing the dorsoventral and caudorostral genetico molecular gradients, which specify the cortical regions during development.
PMID: 12599114 [PubMed – in process]
2: FEBS Lett 2003 Feb 11;536(1-3):209-14
Expression of syntaxin 1C, an alternative splice variant of HPC-1/syntaxin 1A, is enhanced by phorbol-ester stimulation in astroglioma: participation of the PKC signaling pathway.
Nakayama T, Mikoshiba K, Yamamori T, Akagawa K.
Department of Physiology, Kyorin University School of Medicine, Tokyo 181-8611, Japan.firstname.lastname@example.org
Syntaxin 1C is an alternative splice variant of HPC-1/syntaxin 1A; the latter participates in neurotransmitter release and is assigned to the gene domain responsible for Williams’ syndrome (WS). It is expressed in the soluble fraction extracted from human astroglioma cell lines T98G and U87MG. Quantitative immunoblot and indirect immunofluorescence analyses revealed that the expression of syntaxin 1C was upregulated by phorbol 12-myristate 13-acetate (PMA), but not by forskolin. A protein kinase C (PKC) inhibitor suppressed this enhancement. These results suggest that syntaxin 1C expression is regulated via the PKC signal pathway. This is the first report of a signal transduction system that directly affects the expression of syntaxin protein.
PMID: 12586365 [PubMed – indexed for MEDLINE]
3: Am J Med Genet 2003 Mar 1;117A(2):169-71
Oligoyric microcephaly in a child with Williams syndrome.
Faravelli F, D’Arrigo S, Bagnasco I, Selicorni A, D’Incerti L, Riva D, Pantaleoni C.
Department of Pediatric Neurology, Besta Institute, Milan, Italy.
We report a 19-month-old boy with microcephaly, growth and developmental delay, facial dysmorphisms, and simplified gyral pattern. Magnetic resonance imaging (MRI) examination demonstrated microcephaly with simplified gyral pattern or oligogyric microcephaly. The facial phenotype was interpreted as suggestive of Williams syndrome (WS). Fluorescence in situ hybridization (FISH) analysis performed with an elastin probe revealed a deletion in the chromosomal band 7q 11.23, confirming the clinical diagnosis. To our knowledge, this represents the first patient with WS and oligogyric microcephaly. Copyright 2002 Wiley-Liss, Inc.
PMID: 12567416 [PubMed – in process]
4: J Med Genet 2003 Feb;40(2):136-40
Using case study comparisons to explore genotype-phenotype correlations in Williams-Beuren syndrome.
Karmiloff-Smith A, Grant J, Ewing S, Carette MJ, Metcalfe K, Donnai D, Read AP, Tassabehji M.
PMID: 12566524 [PubMed – indexed for MEDLINE]