Interstitial deletion of chromosome 7q in a patient with Williams syndrome and infantile spasms.

Interstitial deletion of 7q11.23-q21.11 was identified by cytogenetic methods in a 4-year-old boy with Williams syndrome (WS) and infantile spasms. Deletion of the elastin (ELN) gene and the DNA polymorphic markers, D7S1870, D7S2490, D7S2518, and D7S2421, were identified in the patient, but the loci for D7S653 and D7S675 were not involved. Zackowski et al. (1990) reported that 6 of 16 patients with the interstitial deletion of 7q11.2-q22 had abnormal electro encephalograms, or seizures, or both, and that infantile spasms were present in 2 of the 6 patients. WS is a well defined developmental disorder characterized by distinct facial features, gregarious personality, and congenital heart defects. Seizures are not generally associated with this syndrome. WS commonly is characterized by deletion of the loci for ELN and D7S1870, but not those for D7S2490, D7S2518, or D7S2421. This suggests that a gene responsible for infantile spasms is located in the 2.7-cM interval between loci D7S1870 and D7S675.

Mizugishi K ，Yamanaka K ，Kuwajima K ，Kondo I ... -  《JOURNAL OF HUMAN GENETICS》

Infantile spasms in two children with Williams syndrome.

We describe two children with Williams syndrome and infantile spasms. The diagnosis of Williams syndrome was confirmed by documentation of a deletion of the elastin gene/Williams syndrome region at 7q11.23. The diagnosis of infantile spasms was confirmed through the presence of interictal hypsarrhythmia. This represents one of the first reports of infantile spasms in the Williams syndrome.

Tsao CY ，Westman JA 《american journal of medical genetics》

Delineation of 7q11.2 deletions associated with Williams-Beuren syndrome and mapping of a repetitive sequence to within and to either side of the common deletion.

The majority of Williams-Beuren syndrome (WBS) patients have been shown to have a microdeletion within 7q11.2 including the elastin gene locus. The extent of these deletions has, however, not been well characterized. Thirty-five deletion patients were tested for all polymorphic markers in the 7q11.2 region bounding ELN to define the extent of deletions associated with WBS. With only one exception, ELN, D7S1870, and one copy of the D7S489 locus (D7S489U) were always included in the deletions. One patient showed lack of maternal inheritance at D7S1870 and not at ELN or D7S489U. A product corresponding to D7S489U was amplified from YAC 743G6 and from the P1 clone RMC07P008, thereby localizing both to within the common deletion. The boundary of the deleted region on the proximal (centromeric) side is D7S653 and on the distal side is D7S675, neither of which were ever included in the deletion. One locus, D7S489L, was variably deleted in patients, indicating a minimum of two common breakpoints on the proximal side. At least one additional repeat amplified by D7S489 (D7S489M) was localized to a YAC contig mapping distal to the common deletion. The D7S489 sequence is highly homologous to several cDNA clones in the GenBank database and contains an Alu sequence. It is possible that this andsolidusor other repetitive sequences in this region could play a role in the mechanism of deletion.

Robinson WP ，Waslynka J ，Bernasconi F ，Wang M ，Clark S ，Kotzot D ，Schinzel A ... -  《GENOMICS》

Deletion of 7q11.21-q11.23 and infantile spasms without deletion of MAGI2.

We report on the clinical and cytogenetic findings and on the array-based characterization of an interstitial 7q11.21-q11.23 deletion initially recognized by standard karyotyping in a 15-month-old female patient. Beginning at the age of 3 months and 2 weeks the patient had severe infantile spasms. Recently, it was reported that infantile spasms are associated with deletion of the MAGI2 gene on chromosome 7q11.23. Nevertheless, not all patients reported with deletions of MAGI2 developed infantile spasms and at least one reported patient with a deletion 7q11.23 without missing the MAGI2 gene was diagnosed with infantile spasms. Molecular karyotyping of our patient confirmed a large 13 Mb deletion encompassing the 7q11.21-q11.23 region without involvement of MAGI2. Critical review of published data and the results of our patient underline the importance to map precisely the deletion boundaries of further patients to reevaluate the significance of MAGI2 hemizygosity in the pathogenesis of infantile spasms.

Röthlisberger B ，Hoigné I ，Huber AR ，Brunschwiler W ，Capone Mori A ... -  《-》

[Genetic diagnosis of Williams syndrome].

Williams syndrome is a complex developmental disorder. The major cardiovascular component of Williams syndrome is supravalvular aortic stenosis, a progressive disease that may need surgical repair. Williams syndrome is associated with heterozygous microdeletion in the chromosomal region 7q11.23 encompassing the elastin gene. We have identified a new, highly informative tetranucleotide repeat polymorphism within the human elastin gene. This marker together with other, previously described elastin gene markers was used to show deletion of the elastin gene in nine sporadic Williams syndrome patients from Hungary. Application of polymorphisms within and flanking the elastin gene on chromosome 7 provides a fast, polymerase chain reaction based method for mutational analysis of Williams syndrome patients.

Urbán Z ，Kiss E ，Kádár K ，Szabolcs J ，Csiszár K ，Boyd DC ，Fekete G ... -  《ORVOSI HETILAP》