David Schnasa Jacobsen, Mark

David J.C. MacKay and Mark N. Gibbs

Jacobsen syndrome

Jacobsen syndrome is a MCA/MR contiguous gene syndrome caused by partial deletion of the long arm of chromosome 11. To date, over 200 cases have been reported. The prevalence has been estimated at 1/100,000 births, with a female/male ratio 2:1. The most common clinical features include pre- and postnatal physical growth retardation, psychomotor retardation, and characteristic facial dysmorphism...

Ocular findings in Jacobsen syndrome.

PURPOSE To discuss the ophthalmic findings and their clinical significance in 10 new cases of Jacobsen syndrome (mental retardation, craniofacial anomalies, congenital heart defects, and blood dyscrasias) and to review the ophthalmic findings in all previously reported cases in the literature. METHODS Ten new cases of Jacobsen syndrome were collected and studied prospectively for detection of...

Nuchal thickening in Jacobsen syndrome.

A routine detailed ultrasound examination performed at 20 weeks' gestation demonstrated the presence of nuchal thickening as an apparently isolated finding. The concentration of maternal alpha-fetoprotein was normal and the risk of Down's syndrome was 1 in 6800. Amniocentesis was performed and chromosome analysis showed the karyotype 46,XY, del(11)(q23) found in Jacobsen syndrome. Fetal autopsy...

Color and the Inverted Spectrum DAVID HILBERT and MARK ELI KALDERON

When we open our eyes, one of the most striking features of the occurrent scene before us is the apparent multitude of colored surfaces, transparent volumes, and radiant light sources.1 Grass, emeralds, and certain lava lamps, for example, all appear green to us. If something visually appears green to us, and it is in fact green, then our visual experience is veridical, at least in part.2 If, o...