Posted by: patoconnor on: October 30, 2008
Distal Trisomy 10q
What is Distal Trisomy 10q? Distal Trisomy 10q is an extremely rare syndrome in which a person has an extra end (distal) portion of chromosome 10, specifically from the long arm (q). This can occur spontaneously at conception (de novo), or most commonly, from a translocation in one of the parents. In the [...]
Posted by: patoconnor on: October 30, 2008
The diagnostic utility of a genetics evaluation in children with pervasive developmental disorders
January 8, 2006
Abstract
Abdul-Rahman OA, Hudgins L.
Division of Medical Genetics, Department of Pediatrics, Stanford University, 300 Pasteur Drive, H-315, Stanford, CA 94305, USA.
PURPOSE:
A genetics evaluation of children with pervasive developmental disorders (PDDs) identifies a diagnosis in 6% to 15% of cases. However, previous [...]
Posted by: patoconnor on: October 30, 2008
Genotype-Phenotype CorrelationsAlthough the size of the deletion in 22q13.3 syndrome ranges from 100 kb to more than 9 Mb, Wilson et al (2003) found that deletion size showed little correlation with the clinical features of this disorder. Their analysis of 56 individuals with deletions ranging from 130 kb to more than 9 Mb revealed that [...]
Posted by: patoconnor on: October 30, 2008
Phelan-McDermid Syndrome – 22q13 deletion – Page One
Author: Katy Phelan, PhD, FACMG
Posted: 11 May 2005
Summary
Disease characteristics. Deletion 22q13.3 is a microdeletion syndrome in which the affected individuals have neonatal hypotonia, normal to accelerated growth, absent to severely delayed speech, global developmental delay, and minor dysmorphic facial features. Other features include large, fleshy hands, dysplastic toenails, [...]
Posted by: patoconnor on: October 30, 2008
This condition was first identified by Dr. Harry Klinefelter at the Massachusetts General Hospital in Boston. A report published he and his coworkers reported case studies on nine men who had enlarged breasts, sparse facial and body hair and an inability to produce sperm.
Now more appropriately referred to as XXY Male of XXY Male [...]
Posted by: patoconnor on: October 30, 2008
What is chromosome 22?
Chromosome 22 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 22 is the second smallest human chromosome, spanning about 49 million base pairs (the building material of DNA) and representing between 1.5 and 2 percent of the total DNA in [...]
Posted by: patoconnor on: October 30, 2008
Trisomy 21
Alternative names
Trisomy 21, Down Syndrome
Definition Return to top
Down syndrome is a chromosome abnormality, usually due to an extra copy of the 21st chromosome. This syndrome usually, although not always, results in mental retardation and other conditions.
Causes, incidence, and risk factors Return to top
In most cases, Down syndrome is caused by an extra [...]
Posted by: patoconnor on: October 30, 2008
What is Trisomy 20?
Trisomy 20 is the name given to a chromosome abnormality where cells contain three copies of chromosome 20 (hence tri-somy) rather than the normal two copies. Trisomy 20 can exist in two states. These are:
(i) Mosaic – hence Trisomy 20 Mosaicism
Click below for more information: [...]
Posted by: patoconnor on: October 30, 2008
Clnics and Pathology
Disease
Trisomy 19 (+19) as a sole karyotypic aberration is strongly associated with myeloid disorder. In a previously published literature review, among 31 patients with isolated +19, 25 were diagnosed with myeloid malignancy, including acute myeloid leukaemia (AML) in 14 cases and myelodysplastic syndrome (MDS) in 11 cases. Four out of the 14 AML [...]
Posted by: patoconnor on: October 30, 2008
Alternative names
Edwards syndrome
Definition
Trisomy 18 is a syndrome associated with the presence of a third (extra) number 18 chromosome.
Causes, incidence, and risk factors
Trisomy 18 is a relatively common syndrome affecting approximately 1 out of 3,000 live births and affecting girls more than three times as often as boys. Multiple abnormalities are [...]
