Research Paper Sample on the Klinefelter Syndrome (XXY)

In 1942, at the Massachusetts General Hospital in Boston, Dr. Harry Klinefelter, and his co-workers compiled a report about nine men who had sparse facial and body hair, enlarged breasts, small testes and were unable to produce sperms. This condition was unique and unknown. By late 1950s, the researchers came to realize that men who expressed such symptoms had an extra chromosome, XXY, instead of the usual XY. It was at this time that the scientists discovered that the condition was a genetic disorder affecting men only and it was named as Klinefelter syndrome following its early discovery and documentation of its symptoms by Dr. Harry Klinefelter. However, the disease has also been referred to as XXY syndrome or KS. It is called XXY syndrome because boys and men with the condition are born with an extra chromosome. Boys and men with Klinefelter syndrome are still genetically men and more often do not realize they have an extra chromosome or XXY syndrome until when they try to have a child but not successful (Amory & Bremner, 2017). The XXY syndrome is relatively common affecting 1 in every 660 males (Amory & Bremner, 2017).

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Cause of Klinefelter Syndrome

Klinefelter syndrome is a genetic disorder. Usually, a normal human being has 46 chromosomes. They are divided into 23 pairs including two sex chromosomes. Half of the chromosomes are inherited from the father and the other half from the mother. Cells that are to become eggs or sperms undergo a process known as meiosis. During meiosis, 46 chromosomes in the cell divide giving rise to two new cells each having 23 chromosomes. However, before meiosis comes to a close, chromosomes pair with corresponding ones to allow for the exchange of genetic material which determines the individual's characteristics such as height and eye color among others. In men, the X and Y chromosomes pair while in women the X chromosomes pair (Nussbaum, McInnes & Willard, 2015). Once the genetic material is exchanged, the chromosomes separate and meiosis proceeds to its completion.

In certain cases, the X and Y chromosomes fail to pair and exchange the genetic material. Instead, each chromosome moves independently to the same cell leading to a sperm with both X and Y chromosome or an egg with two X chromosomes (Nussbaum et al., 2015). When a sperm containing X and Y chromosomes fuses with an egg containing an X chromosome or in another instance a normal sperm with Y chromosome fuses with an egg containing two X chromosomes, an XXY boy is conceived (Nussbaum et al., 2015). This male will grow up with an extra chromosome responsible for expression of symptoms of Klinefelter syndrome.

Symptoms of Klinefelter Syndrome

Klinefelter does not always cause obvious symptoms among the males having an extra chromosome in their genetic makeup. However, in noticeable cases, some symptoms are apparent. In babies with XXY syndrome, their muscles are weak coupled with reduced strength and quite personality (Paduch & Ryan, 2015). Consequently, such young boys take a longer time than a normal child would take to sit up, crawl, walk and speak. For example, instead of a boy child beginning to walk latest at the age of 15 months, an XXY child would delay to about two years.

The XXY syndrome typically interferes with the normal production of testosterone in males. The testicles do not produce sufficient amounts of sperms consequently making it difficult for an XXY male to father a child (Paduch & Ryan, 2015).

Testosterone influences the way a boy develops sexually and physically. Eventually, small amounts of testosterone among XXY males lead to sexual symptoms such as delayed puberty or its absence at all, low sex drive and infertility (Paduch & Ryan, 2015). Physically, the XXY males demonstrate weaker bones, low energy levels, less facial and body hair after puberty, broader hips and long legs and arms as well as larger breasts (Paduch & Ryan, 2015).

At childhood, sometimes the XXY boys demonstrate low self-esteem. For example, he is mostly shy. Also, young boys with Klinefelter syndrome have difficulties with reading, spelling, writing and paying attention (Paduch & Ryan, 2015). They may present with mild dyspraxia and dyslexia. Moreover, they have difficulties with socializing and expressing their feelings in the presence of their peers (Paduch & Ryan, 2015).

It has also been found that XXY males exhibit abnormal growth among the family members. For example, they may be overweight, a characteristic not common among the family members. Similarly, they may grow taller and slender than their parents and siblings (Paduch & Ryan, 2015). Such a male is tall but quite weak due to weak bones and lack of masculinity.

Genetic Basis and Inheritance Pattern of Klinefelter Syndrome

Normally, people have a total of 46 chromosomes, two in each cell. Females have two X chromosomes (46, XX) whereas males have a single X and Y chromosomes (46, XY). However, XXY males or men with Klinefelter syndrome exhibit the presence of an extra copy of the X chromosome in each of their cells making a (47, XXY) (Wistuba, Brand, Zitzmann & Damm, 2017). The extra copy of X chromosome interferes with normal functioning of a male especially with the reduction in levels of testosterone hence such an individual exhibits the Klinefelter's syndrome symptoms.

XXY syndrome and its variants are usually not inherited; rather they are developmental disorders. Chromosomal changes leading to Klinefelter syndrome occur as random events during the process of meiosis where sperms and eggs are manufactured (Wistuba et al., 2017). An error in cell division or an inheritance pattern known as nondisjunction takes place leading to a reproductive cell (sperm or egg) with an abnormal number of chromosomes.

Nondisjunction is a situation in which the chromosomes fail to separate correctly leading to gametes with one missing or one extra chromosome (Nussbaum, McInnes & Willard, 2015). Usually, nondisjunction occurs at meiosis I and II when the cell division for gamete formation occurs. In meiosis, gametes are formed when a single cell divides into four through combined processes of meiosis I and II. During meiosis I, each pair of homologous chromosomes lines up next to each other as it prepares to divide to make gametes. Nondisjunction results when the homologous chromosomes fail to separate (Nussbaum et al., 2015). Consequently, one cell has two copies of a chromosome. For example, instead of a male cell containing an X and Y chromosome, it will have two Xs resulting in chromosomal abnormalities.

During the meiosis II, the cell divides and goes from diploid to haploid as the cell prepares for fertilization. Where a pair of sister chromatids does not properly separate during the anaphase of meiosis II, one daughter cell will be missing a chromosome when the other one is having an extra one, an inheritance pattern known as nondisjunction (Nussbaum et al., 2015). For instance, instead of an egg resulting from meiosis II having a single X chromosome, it will have two so that when it fuses with the male sperm, an XXY is formed, and a boy child with Klinefelter syndrome is born.

Molecular Basis for Klinefelter Syndrome and Mechanism through Which it Gets Translated into Phenotype

When nondisjunction occurs, particularly during meiosis II, a cell will have an extra or missing chromosome. Where a cell has an extra chromosome, it will have 47 instead of the normal 46. This is referred to as sex chromosome aneuploidy and is a mechanism by which genetic abnormalities get expressed phenotypically (Zitzmann et al., 2015). Normally, a male will have two X chromosomes while a man has one X and one Y. Due to sex chromosome aneuploidy, a male with two X chromosomes and a single Y chromosome is born (47, XXY). The presence of an extra X chromosome is responsible for abnormalities observed in XXY males especially where small amounts of testosterone are produced from smaller testes present in such males. The small amounts of testosterone inhibit muscular and male sexual developments leading to individuals with enlarged breasts and broader hips among other unusual physical characteristics among XXY males (Zitzmann et al., 2015).

Treatment of Klinefelter Syndrome

The XXY condition is something an individual is born with, and there is no way to change it. However, treatment can be effected to help relieve some of the phenotypic symptoms. The effectiveness of such treatments can be enhanced if an individual is diagnosed early and treatment initiated. There are two useful treatments for XXY males; testosterone replacement therapy (TRP) and educational support services.

Testosterone Replacement Therapy (TRP)

TRP is treatment by which an XXY male receives additional testosterone into his body through a regular schedule of injection. TRP therapy aims to increase testosterone levels in the body to normal range. As a result, an XXY syndrome individual will develop facial and body hair, stimulate the growth of the penis and promote the growth of bigger muscles and deeper voice (Paduch & Ryan, 2015). TRP also reduces the growth of male breasts while at the same time improving bone density and enhancing strength (Paduch & Ryan, 2015). Nonetheless, TRP treatment cannot increase the size of testicles neither can it reverse infertility.

In addition to physical changes, TRP treatment brings on psychological changes too. As the testosterone helps XXY males develop masculine appearance, they regain self-confidence (Paduch & Ryan, 2015). Other males have demonstrated a tendency of becoming more energetic and ceased having sudden mood changes such as anger. This is because testosterone reduces depressive disorders among the XXY males as they can now fit in with other boys or men of their age.

Moreover, TRP treatment may incur other benefits to the XXY males. These may include decreased need for sleep, improved relations with others and enhanced ability to concentrate especially in school activities (Paduch & Ryan, 2015).

Educational Support Services

XXY males often exhibit difficulties with reading and writing among other problems that affect their academic performance. To help them keep pace in school, special support services and treatments may be necessary. As a first step, the parent should inform the school and the nurse to see what support may be available and helpful to the child. Often, such children are eligible for the 504 education plan or individualized education plan (IEP). Both of these education plans can meet the special needs of XXY boys (Paduch & Ryan, 2015).

Likewise, XXY boys can be assisted academically through physical and speech therapies. Such therapies will help them speak, write and read better as well as enhancing their muscle strength and coordination (Paduch & Ryan, 2015). They may also be enrolled for mental, behavioral and occupational therapies to help them deal with psychological and physical problems they may experience such as shyness, low-self esteem and delayed social development (Paduch & Ryan, 2015).

Prognosis of Klinefelter Syndrome

Children with Klinefelter syndrome differ slightly from the healthy ones. XXY infants younger than two years have normal facial features, normal external genitalia, and weight (Aksglaede, Petersen, Main, Skakkebaek & Juul, 2017). Nonetheless, XXY boys could struggle various frustrations including academic challenges, behavioral and emotional difficulties (Paduch & Ryan, 2015). But a majority of XXY males attain full independence from their families as they transition to adulthood. For example, some of the XXY men have completed graduate education and are functioning normally (Paduch & Ryan, 2015). This means that Klinefelter syndrome may not affect the lifespan of...