For a century, scientists studied chromosomes by looking at them under a microscope. In order for chromosomes to be seen this way, they need to be stained. Once stained, the chromosomes look like strings with light and dark bands, and their picture can be taken. A picture, or chromosome map, of all 46 chromosomes is called a karyotype. The karyotype can help identify abnormalities in the structure or the number of chromosomes.
To help identify chromosomes, the pairs have been numbered from 1 to 22, with the 23rd pair labeled "X" and "Y." In addition, the bands that appear after staining are numbered, the higher the number, the farther that area is from the centromere.
In the past decade, newer techniques have been developed that allow scientists and doctors to screen for chromosomal abnormalities without using a microscope. These newer methods compare the patient's DNA to a normal DNA sample. The comparison can be used to find chromosomal abnormalities where the two samples differ. …show more content…
This is a test to screen a pregnancy to determine whether a baby has an increased chance of having specific chromosome disorders. The test examines the baby's DNA in the mother's blood.
Williams Syndrome
Williams syndrome is a rare disorder that can lead to problems with development. It is passed down in the offsprings of families.
One of the 25 missing genes is the one that produces elastin, a protein that allows blood vessels and other tissues in the body to stretch. It is likely that missing a copy of this gene results in the narrowing of blood vessels, stretchy skin, and flexible joints seen in this condition.
Symptoms of Williams syndrome are:
Delayed speech that may later turn into strong speaking ability and strong learning by hearing.
Developmental delay.
Easily distracted, attention deficit disorder, also known as ADD.
Feeding problems such as colic, reflux, and
To help identify chromosomes, the pairs have been numbered from 1 to 22, with the 23rd pair labeled "X" and "Y." In addition, the bands that appear after staining are numbered, the higher the number, the farther that area is from the centromere.
In the past decade, newer techniques have been developed that allow scientists and doctors to screen for chromosomal abnormalities without using a microscope. These newer methods compare the patient's DNA to a normal DNA sample. The comparison can be used to find chromosomal abnormalities where the two samples differ. …show more content…
This is a test to screen a pregnancy to determine whether a baby has an increased chance of having specific chromosome disorders. The test examines the baby's DNA in the mother's blood.
Williams Syndrome
Williams syndrome is a rare disorder that can lead to problems with development. It is passed down in the offsprings of families.
One of the 25 missing genes is the one that produces elastin, a protein that allows blood vessels and other tissues in the body to stretch. It is likely that missing a copy of this gene results in the narrowing of blood vessels, stretchy skin, and flexible joints seen in this condition.
Symptoms of Williams syndrome are:
Delayed speech that may later turn into strong speaking ability and strong learning by hearing.
Developmental delay.
Easily distracted, attention deficit disorder, also known as ADD.
Feeding problems such as colic, reflux, and