Klinefelter syndrome is the most common genetic disorder occurring in males leading to occurrence of hypogonadism and infertility. Klinefelter syndrome or klinefelter’s syndrome also known as XXY syndrome as the name itself represent is a genetic disorder in which there is presence of one extra chromosome in the normal karyotype.
In klinefelter’s syndrome there are 47 chromosomes present rather than 46 chromosomes found in genetically normal humans. That extra one chromosome is X chromosome leading to change in normal genetic genome of 46 chromosomes to 47 chromosomes.
This extra chromosome represents its own features in an individual.Females have an XX chromosomal makeup and males have XY, individuals with klinefelter syndrome have at least two X chromosomes and at least one Y chromosome. Individuals who posses this extra chromosome are usually referred to as XXY males or 47, XXY males”.
Due to occurrence of this extra chromosome in males, as it is a female chromosome so it leads to develop features due to this the most common features which represent klinefelter’s syndrome are hypogonadism and infertility.
This syndrome is characterized by hypogonadism (small testes, azoospermia, and oligospermia) in late puberty there occur gynecomastia, psychosocial problems, in seminiferous tubules there occur fibrosis and increase in urinary gonadotrophin levels.
X chromosome carries genes that play roles in many systems of the body including function of gonads, development of brain and growth. With the addition of extra X chromosome in the normal genotype which leads to many physical and cognitive abnormalities such as mental retardation. Affect of this extra chromosome on different systems of the body are as follows
• This extra chromosome is usually acquired through an error of nondisjunction during parental gametogenesis.
• There occur severe skeletal and cardiovascular abnormalities of the individuals who are affected with klinefelter’s syndrome.
• Due to addition of this extra X chromosome affects the overall growth of different parts of body most commonly affected are reproductive system, skeletal system and brain. In gonadal development it leads to dysgenesis of somniferous tubules and infertility, along with that occur hypo plastic and malformed genitalia.
• Mental capacity of the patient is not like a normal individual who possess 46 chromosomes. The intelligent quotient score of the patient suffering from klinefelter’s syndrome is reduced by 15 points.
• Major sensory areas are affected like language, coordination and expression.
• Males who suffer from klinefelter’s syndrome are on higher risk of acquiring autoimmune diseases, diabetes mellitus, leg ulcers, and osteoporosis, tumors of breast and germ cells, rheumatoid arthritis, systemic lupus erythematous.
In klinefelter’s syndrome there occurs primary testicular failure with increase in gonadotrophin levels due to lack of feedback inhibition by pituitary gland.
As there occur androgen hormone deficiency this lead to sparse or absent facial, pubic, axillary or body hair, muscle mass and strength is less, there is feminine distribution of adipose tissue, gynecomastia testes and penis are small.
Who Are At Risk?
Klinefelter’s syndrome as the term suggest occurrence of X chromosome in individual who already have XY chromosome so it affects males.
The major cause of klinefelter syndrome is the variation in genes. The extra x chromosome is retained at the time of gametogenesis (meosis 1) due to non-dysjunction.
• In children muscles are weaker and strength is reduced.
• The children who are suffering from this syndrome they tend to become taller than average.
• Body of the male have less facial and body hair, broader hips and less muscular body.
• Males may have larger breasts, weaker bones and low energy levels.
• Patient has rounded body type with some degree of gynecomastia.
• Affected males are infertile or reduced fertility.
Examination of the patient is the first step to investigate the case and this will review following points
• Secondary sexual organs are absent.
• Testes small in size.
• Enlargement of breast in males.
Other investigations are as follows
• Barr body observation is helpful to diagnose.
• Karyotype on lymphocytes will help to diagnose.
• Determination of sex chromatin.
• High serum levels of gonadotrophin hormones.
• High levels of FSH (follicle stimulating hormone).
• High levels of luteinizing hormone.
• Fragile X syndrome.
• Kallman syndrome.
• Marfan syndrome.
When treatment is started at early age, then some cases can be treated and can lead normal life. But the cases in which the patient lost his sexual functions totally difficult to treat case.
As it is a genetic abnormality change of karyotype is not possible.
Complication can be treated with medication like tumors, cardiovascular abnormalities.
• The genetic reversal is not possible as it is a permanent change in the karyotype.
• Gynaecomastia can be treated surgical procedures.
• Hormone disturbances can be treated by giving hormone therapy.
• Patients who are under psychological stress due to klinefelter’s syndrome can be treated by counseling.
Why not ask your query directly to Dr. Thind’s team? Get an expert opinion FOR FREE!