Philadelphia chromosome

Research into the genetics of deafness has shown that mutations in the CX26 gene, located on human chromosome 13q11, cause non-syndromic recessive deafness (9, 10). Expression of GJB2 has been documented in a variety of cells and tissues. In the cochlea, CX26-containing gap junctions are proposed to maintain K homeostasis by ferrying K away from the hair…

Environmental-Dependent Sex Determination in Reptilians When we think of sex determination in organisms, we most often think of mitosis and the process of randomly receiving X and Y chromosomes from parent cells. This type of sex determination is known as genotypic sex determination (GSD), and it’s the most commonly found method of sex determination. However, this isn’t the only type of sex determination available to organisms. Some reptilians, for example, use environmental-dependent sex…

Barbra McClintock was born June 16, 1902, in Hartford, Connecticut (Editors). The third of four children born to physician Thomas McClintock and wife Sarah, McClintock was christened Eleanor, though her parents soon began to call her Barbra believing the nickname better suited her pragmatic demeanor (“Barbra McClintock”). Barbra demonstrated an interest in science from a young age, perhaps influenced by her father’s profession (Editors). At the age of seventeen, she graduated from high school…

Progeria also known as Hutchinson-Gilford Progeria syndrome is an extremely rare genetic disease where a person is born with the characteristics of an aged body. The word Progeria comes from the greek words “pro” meaning premature and “geras” meaning old age. This genetic disease only occurs in an estimated 1 in 8 million individuals, and there are no hereditary factors or environmental factors which affect the cause of progeria. The average life of an individual with Progeria is usually between…

3 Chromosomes are thread-like structures which consist of DNA and other proteins. Chromosomes are present in every cell of the human body so that information can be carried for that cell to develop. The human body normally consists of 46 chromosomes which then can be paired into 23 pairs. 22 pairs of chromosomes are similar in both males and females which are commonly known as autosomes. However, the 22nd chromosomes (X and Y) are different as these are the sex chromosomes. The human cell can…

additional chromosome. Trisomy 13 is a chromosomal disorder that affects either all or a portion of the 13th chromosome. Each person is given a set of chromosomes, one from mom and the other from dad. During embryo development, the 13th chromosome takes on an additional set from either parent. This results in a set of three chromosomes. The severity of the abnormality associated with Trisomy 13 depends on the specific location and percentage of the duplicated cell in the 13th chromosome. …

remaining 40% being hereditary. Usually, 25% of the hereditary cases have family disease history, which is what we have in this case (NORD). Bilateral retinoblastoma is caused by a “two-hit” mutation on the RB1 gene, which is located on the long arm of chromosome 13, on band 14. The “two” in the two-hit mechanism is referring to the two alleles of the RB1 gene (Knudson, 1971). The first hit in the heritable form of the disease is a heterozygous germline mutation. The other hit is usually a…

imprinting disorder caused by the failure to express SNRPN (small nuclear ribonucleoprotein-associated polypeptide N) gene product. SNRPN is expressed only on the paternal chromosome 15q11-q13, however, the exact genes responsible for Prader-Willi syndrome haven't been identified. People normally inherit one copy of chromosome 15 from each parent. Some genes are active only on the copy that is inherited from a person's father, the paternal copy. Genomic imprinting causes this parent specific…

Edwards syndrome also known as Trisomy 18 occurs in about 1 out of every 2500 pregnancies in the United States alone. This genetic diseases causes severe development delays due to an extra chromosome. Down syndrome is also caused because of an extra chromosome, however the difference between these two is that Edwards syndrome deals with more medical complications and has a higher risk factor on the early months and years of life. It usually occurs during the sperm and egg formation. The disease…

“Who made what?” After learning the different variations of genetic traits passed down to the offspring, my team and I were influenced to conduct research regarding the genetic variations of fruit flies. “Which mode of inheritance do the yellow body and curly wing trait follow?” After coordinating research, it is evident that: Because only 2 yellow bodies can only reproduce other yellow bodies, Curly wings can have either Curly or Wild-wing off spring, and the characteristics of dominant and…