cytogenetics 6

Cytogenetics 201Lec 6. : 

Cytogenetics 201Lec 6. Hussein Sabit, Ph.D

This lecture will cover: : 

This lecture will cover: Intersex conditions Y chrmomsome disorders X chrmomsome disorders Hussein Sabit, Ph.D

Intersex conditions: : 

Intersex conditions: Introduction A congenital abnormality of the reproductive and sexual organs which in some cases can make it difficult to determine the sex of the child. There is much debate over who gets to decide what gender the child should be - the child or the parents. Hussein Sabit, Ph.D

gender identity disorders: : 

gender identity disorders: Sexual disorders that involve gender identity produce persistent feelings of gender discomfort and dissatisfaction. Gender identity is defined as the psychological state reflecting a sense of being male or female. It’s based culturally on determined sets of attitude behavior patterns and other attributes usually associated with masculinity or femininity. Gender identity disorders shouldn’t be confused with the more common feelings of inadequacy in fulfilling the expectations normally associated with a particular sex. Hussein Sabit, Ph.D

Gender Identity Disorder: : 

Gender Identity Disorder: A condition where the sufferer believes that he/she has been assigned the wrong gender. This condition often leads transexuality or cross-dressing and some even resort to a sex-change operation to give them the physical attributes they believe they should have been born with. Symptoms of Gender Identity Disorder Confusion about gender identity Distress about gender identity Belief that person should be the other gender Cross-dressing Hussein Sabit, Ph.D

Disease Topics Related To Intersex conditions : 

Disease Topics Related To Intersex conditions 5-alpha reductase deficiency Androgen insensitivity syndrome Congenital adrenal hyperplasia Hussein Sabit, Ph.D

Cont. : 

Cont. Paranoid Personality disorders Schizoid Personality disorders Avoidant Personality disorders Dissocial Personality disorders Hussein Sabit, Ph.D

Causes and incidence : 

Causes and incidence Current theories about gender identity disorders and their causes suggest a combination of predisposing factors: chromosomal anomaly, hormonal imbalance (occurring particularly during brain formation in uterus), and impaired early parent-child bonding and child-rearing practices. Gender identity disorders, which are rare, may occur in children and adults. Hussein Sabit, Ph.D

Signs and symptoms : 

Signs and symptoms A gender identity disorder may emerge at an early age. A child may express the desire to be — or insist that he or she is — the opposite sex. For example, a male child may express disgust with his genitalia; a female child may wish to be a man when she grows up. Men with a gender identity disorder may describe a lifelong history of feeling feminine and pursuing feminine activities. Women report similar propensities for opposite-sex activities and discomfort with the female role. For both sexes, the crisis intensifies during puberty. Hussein Sabit, Ph.D

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Treatment Individual and family therapy is indicated for childhood gender identity disorders. Individual and couples therapy may help adults cope. Sex reassignment through hormonal and surgical treatment may be an option; however, it’s a highly controversial measure that’s undergoing much identification. Severe psychological problems may persist after sex reassignment. Furthermore, the patient’s gender disorder may be part of a larger depression and personality disorder pattern. Hussein Sabit, Ph.D

Gender identity disorder includes : 

Gender identity disorder includes Y disorders X disorders Hussein Sabit, Ph.D

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Y Chromosome Disorders: Introduction The Y chromosome is a sex-linked chromosome. Men are XY and women are XX, so only men have a Y chromosome. The Y chromosome is very small and contains few genes. There are few genetic diseases related to genes on Y. Hussein Sabit, Ph.D

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The Y Chromosome Theory: Why Women Are Better Than Men? Hussein Sabit, Ph.D

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For years, scientists have researched the basic differences between human males and human females. While it has been previously declared that what determines gender are the "X" and "Y" chromosomes found in male sperm, this is only partially true. As it turns out, the "Y" chromosome is, in fact, a defective "X" chromosome with one of the legs missing. At first this discovery baffled scientists, but further research has determined that this mysterious missing leg physically manifests itself on the outer body of a male, resulting in what is commonly known as a penis Hussein Sabit, Ph.D

Y Chromosome Infertility : 

Y Chromosome Infertility Disease characteristics.  Y chromosome infertility is characterized by azoospermia (absence of sperm), severe, moderate , or mild oligozoospermia. Males with Y chromosome infertility usually have no obvious symptoms. Management.  Treatment of manifestations: Pregnancies may be achieved by in vitro fertilization using ICSI (intracytoplasmic sperm injection), an in vitro fertilization procedure in which spermatozoa retrieved from ejaculate (in males with oligozoospermia) or extracted from testicular biopsies (in males with azoospermia) are injected into an egg harvested from the reproductive partner. Hussein Sabit, Ph.D

X Chromosome disorder : 

X Chromosome disorder Hussein Sabit, Ph.D

Diseases Linked to the Sex Chromosome X : 

Diseases Linked to the Sex Chromosome X In the past century we have come so far in genetic sciences as to be able to determine exactly what gene or genes cause birth defects or diseases. While many of these diseases are linked to autosomal chromosomes - the non-sex linked chromosomes, 22 of the 23 chromosomes - there are some  which are linked to the sex chromosomes, also known as the X and Y chromosomes. Such diseases as Cystic Fibrosis, Huntington Disease, and Sickle Cell Anemia, are all notorious autosomal diseases. However, diseases like Hemophilia and Diabetes are linked to the sex chromosomes. Hussein Sabit, Ph.D

Fragile X syndrome : 

Fragile X syndrome Definition Fragile X syndrome is a genetic condition involving changes in part of the X chromosome. It is the most common form of inherited mental retardation in males and a significant cause of mental retardation in females. Hussein Sabit, Ph.D

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Alternative Names Martin-Bell syndrome; Marker X syndrome Causes, incidence, and risk factors Fragile X syndrome is caused by a change in the FMR1 gene. The gene's code is repeated on a fragile area of the X chromosome. The more repeats, the more likely there is to be a problem. Normally, the FMR1 gene makes a protein you need for your brain to grow properly. A defect in this gene makes your body produce too little amount of that protein, or none at all. Boys and girls can both be affected, but because boys have only one X chromosome, a single fragile X is likely to affect them more severely. You can have Fragile X syndrome even if your parents do not have it. Hussein Sabit, Ph.D

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Symptoms Mental retardation Large testicles (macro-orchidism) after the beginning of puberty Large body size Tendency to avoid eye contact Hyperactive behavior Large forehead or ears with a prominent jaw Family members who have fewer repeats in the FMR1 gene may not have mental retardation, but may have other problems. Women with less severe changes may have premature menopause or difficulty becoming pregnant. Both men and women may have problems with tremors and poor coordination. Hussein Sabit, Ph.D

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Signs and tests The person will have a family history of Fragile X syndrome (especially a male relative). There are very few outward signs of Fragile X syndrome in babies. Babies may have a large head circumference. Measurement of oversized testes in males who have reached puberty may also suggest the diagnosis. An experienced geneticist may note subtle differences in facial characteristics. Mental retardation is the hallmark of this condition and, in females, this may be the only sign of the problem. A specific genetic test called polymerase chain reaction (PCR) is used to diagnose this disease. This test looks for an expanded mutation (called a triplet repeat) in the FMR1 gene. Hussein Sabit, Ph.D

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Hussein Sabit, Ph.D

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Klinefelter Syndrome Hussein Sabit, Ph.D

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In 1942, Dr. Harry Klinefelter and his coworkers at the Massachusetts General Hospital in Boston published a report about nine men who had enlarged breasts, sparse facial and body hair, small testes, and an inability to produce sperm. Hussein Sabit, Ph.D

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Causes No one knows what puts a couple at risk for conceiving an XXY child. Advanced maternal age increases the risk for the XXY chromosome count, but only slightly. Furthermore, recent studies conducted by NICHD grantee Terry Hassold, a geneticist at Case Western Reserve University in Cleveland, OH, show that half the time, the extra chromosome comes from the father. Hussein Sabit, Ph.D

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Hussein Sabit, Ph.D

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Signs and symptoms Affected males are almost always effectively infertile, although advanced reproductive assistance is sometimes possible. Some degree of language learning impairment may be present, and neuropsychological testing often reveals deficits in executive functions. In adults, possible characteristics vary widely and include little to no signs of affectedness, a lanky, youthful build and facial appearance, or a rounded body type with some degree of gynecomastia (increased breast tissue). Gynecomastia is present to some extent in about a third of affected individuals, a slightly higher percentage than in the XY population, but only about 10% of XXY males' gynecomastia is noticeable enough to require surgery. Hussein Sabit, Ph.D

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The more severe end of the spectrum of symptom expression is also associated with an increased risk of germ cell tumors, breast cancer, and osteoporosis, risks shared to varying degrees with females. Additionally, medical literature shows some individual case studies of Klinefelter's syndrome coexisting with other disorders, such as pulmonary disease, varicose veins, diabetes mellitus, and rheumatoid arthritis, but possible correlations between Klinefelter's and these other conditions are not well characterized or understood. In contrast to these potentially increased risks, it is currently thought that rare X-linked recessive conditions occur less frequently in XXY males than in normal XY males, since these conditions are transmitted by genes on the X chromosome, and people with two X chromosomes are typically only carriers rather than affected by these X-linked recessive conditions. Hussein Sabit, Ph.D

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Treatment The genetic variation is irreversible. Testosterone treatment is an option for some individuals who desire a more masculine appearance and identity. Often individuals that have noticeable breast tissue or hypogonadism experience depression and/or social anxiety because they are outside of social norms. This is academically referred to as psychosocial morbidity. At least one study indicates that planned and timed support should be provided for young men with Klinefelter syndrome to ameliorate current poor psychosocial outcomes. Hussein Sabit, Ph.D

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Hussein Sabit, Ph.D

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49, XXXXY Syndrome is a very rare sex chromosome abnormality with an approximate incidence of 1 in 85,000 male births.  Sometimes, 49, XXXXY Syndrome is referred to as a variant of Klinefelter Syndrome.  Klinefelter Syndrome is a sex chromosome abnormality in which boys have an extra X chromosome and therefore have 47, XXY.  Today, most people distinguish Klinefelter Syndrome from 49, XXXXY Syndrome and other sex chromosome abnormalities because the clinical features can be very different. Hussein Sabit, Ph.D

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Pathophysiology As its name indicates, a person with the syndrome has one Y chromosome and four X chromosomes on the 23rd pair, thus having 49 chromosomes rather than the normal 46. As is common with aneuploidy disorders, 49, XXXXY syndrome is often accompanied by mental retardation. It can be considered a form of Klinefelter syndrome,or a variant of it. It is genetic, but not hereditary. This means that while the genes of the parents cause the syndrome, there is a small chance of more than one child having the syndrome. The probability of inheriting the disease is about 1%. The individuals with this syndrome are males, but a female version also exists with similar characteristics as the male version. Hussein Sabit, Ph.D

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Effects Aneuploidy is often fatal, but in this case there is "X-inactivation" where the effect of the additional gene dosage due to the presence of extra X chromosomes is greatly reduced. The mental effects of 49, XXXXY Syndrome vary, much like Down syndrome. Impaired speech and behavioral problems are typical. Those with 49 XXXXY syndrome tend to exhibit infantile secondary sex characteristics with sterility in adulthood and have some skeletal anomalies. Skeletal anomalies include: fifth finger clinodactyly cleft palate club feet respiratory conditions short or/and broad neck low birth weigh hyperextensible joints short , stature narrow shoulders. Hussein Sabit, Ph.D

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Hussein Sabit, Ph.D

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Hussein Sabit, Ph.D

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Hussein Sabit, Ph.D

XXYY syndrome : 

XXYY syndrome 48,XXYY syndrome is a sex chromosome anomaly. It was previously considered to be a variation of Klinefelter's syndrome It is still considered a part of the syndrome by some definitions.The zygote contains two sex chromosomes, one from the mother and one from the father. Usually, females have two X chromosomes (XX) and males have one X and one Y chromosome (XY). The appearance of at least one Y chromosome makes a male. Therefore, XXYY only affects males. Males affected with XXYY Syndrome have 48 chromosomes instead of the typical 46. This is why XXYY Syndrome is sometimes written as 48, XXYY Syndrome. Typically, males do not have barr bodies, but males affected by XXYY syndrome have one, like females. Normal males only have 1 X chromosome, so barr body inactivation typically does not occur. Hussein Sabit, Ph.D

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History The first published report of a boy with a 48,XXYY karyotype was by Sylfest Muldal and Charles H. Ockey in Manchester, England in 1960. It was found in a 15-year-old mentally challenged boy who had signs of Klinefelter syndrome; eventually, it appeared that he didn't have the Klinefelter Syndrome but, as shown above, the XXYY syndrome. It affects one in every 18,000-40,000 male births. Hussein Sabit, Ph.D

Presentation : 

Presentation Developmental delays, Speech impairment Behavior outburst & mood swings Learning disabilities, Intellectual impairment Autism spectrum disorders Low muscle tone Flat feet, Sterility Delayed sexual development, Undescended testes, Low testosterone Hussein Sabit, Ph.D

A case of a 17-year old boy with extensive ulcers on both lower legs is presented. Clinical examination showed an unusually tall stature, obesity . Chromosomal analysis revealed a karyotype of 48,XXYY. Possible etiologies include chronic venous insufficiency and microvascular disturbances as a consequence of fibrinolytic abnormalities. : 

A case of a 17-year old boy with extensive ulcers on both lower legs is presented. Clinical examination showed an unusually tall stature, obesity . Chromosomal analysis revealed a karyotype of 48,XXYY. Possible etiologies include chronic venous insufficiency and microvascular disturbances as a consequence of fibrinolytic abnormalities. Hussein Sabit, Ph.D

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Hussein Sabit, Ph.D

Turner syndrome or Ullrich-Turner syndrome : 

Turner syndrome or Ullrich-Turner syndrome encompasses several conditions, of which monosomy X (absence of an entire sex chromosome) is most common. It is a chromosomal disorder in which all or part of one of the sex chromosomes is absent. Typical females have 2 X chromosomes, but in Turner syndrome, one of those sex chromosomes is missing or has other abnormalities. In some cases, the chromosome is missing in some cells but not others, a condition referred to as mosaicism or 'Turner mosaicism'. Hussein Sabit, Ph.D

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Occurring in 1 out of every 2500 girls, the syndrome manifests itself in a number of ways. There are characteristic physical abnormalities, such as short stature, swelling, broad chest, low hairline, low-set ears, and webbed necks. Girls with Turner syndrome typically experience gonadal dysfunction (non-working ovaries), which results in amenorrhea (absence of menstrual cycle) and sterility. Concurrent health concerns are also frequently present, including congenital heart disease, hypothyroidism (reduced hormone secretion by the thyroid), diabetes, vision problems, hearing concerns, and many other autoimmune diseases. Hussein Sabit, Ph.D

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Hussein Sabit, Ph.D

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Incidence Approximately 98 percent of all fetuses with Turner syndrome result in miscarriage. Turner syndrome accounts for about 10 percent of the total number of spontaneous abortions in the United States. The incidence of Turner syndrome in live female births is believed to be 1 in 250 Hussein Sabit, Ph.D

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Cause According to Sybert, 1998 the data is inadequate to allow conclusions about phenotype-karyotype correlations in regard to cardiovascular malformations in Turner syndrome because the number of individuals studied within the less common karyotype groups is too small. Other studies also suggest the presence of hidden mosaicisms that are not diagnosed on usual karyotypic analyses in some patients with 45,X karyotype. In conclusion, the associations between karyotype and phenotypic characteristics, including cardiovascular malformations, remain questionable. Hussein Sabit, Ph.D

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Treatment As a chromosomal condition, there is no cure for Turner syndrome. However, much can be done to minimize the symptoms. For example: Growth hormone, either alone or with a low dose of androgen, will increase growth and probably final adult height. Hussein Sabit, Ph.D

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Hussein Sabit, Ph.D

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Triple X syndrome From Wikipedia, the free encyclopedia Jump to: navigation, search Triple X syndrome Classification and external resources ICD-10 Q97.0 DiseasesDB 13386 Triple X syndrome is a form of chromosomal variation characterized by the presence of an extra X chromosome in each cell of a human female. The condition is also known as triplo-X, trisomy X, XXX syndrome, and 47,XXX aneuploidy. Triple X results during division of a parent's reproductive cells and occurs about once in every 1,000 births. Unlike most other chromosomal conditions (such as fragile X), there is usually no distinguishable difference to the naked eye between women with triple X and the rest of the female population. Hussein Sabit, Ph.D

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Cause Triple X syndrome is not inherited, but usually occurs as an event during the formation of reproductive cells (ovum and sperm). An error in cell division called nondisjunction can result in reproductive cells with additional chromosomes. For example, an oocyte or sperm cell may gain an extra copy of the X chromosome as a result of the nondisjunction. If one of these cells contributes to the genetic makeup of a child, the child will have an extra X chromosome in each of her cells. In some cases, trisomy X occurs during cell division in early embryonic development. Some females with triple X syndrome have an extra X chromosome in only some of their cells. These cases are called 46,XX/47,XXX mosaics. Hussein Sabit, Ph.D

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Symptoms This section does not cite any references or sources.Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (May 2008) Due to the Lyonization, inactivation and formation of a Barr body, in all female cells, only one X chromosome is active at any time in a female cell. Thus, triple X syndrome most often causes no unusual physical features or medical problems. Females with the condition may have menstrual irregularities, and, although rarely exhibiting severe mental impairments, have an increased risk of learning disabilities, delayed speech, deficient language skills, and delayed development of motor skills. Hussein Sabit, Ph.D

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An individual producing a child with the above abnormalities has higher than average risk to produce more. Most commonly, there is no observable difference in triple X, other than being taller than average. The additional X chromosome can come from either the maternal or paternal side. The condition is verified only by karyotype testing. Most women with triple X have normal sexual development. Some experience an early onset of menstruation. Triple X women are rarely diagnosed, apart from pre-natal testing methods, such as amniocentesis and blood tests for medical reasons later in life. Most medical professionals do not regard the condition a disability. However, such status can be sought by parents for early intervention treatment if mild delays are present. Hussein Sabit, Ph.D

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Incidence Triple X syndrome occurs in around 1 in 1,000 girls. On average, five to ten girls with triple X syndrome are born in the United States each day.[1 Hussein Sabit, Ph.D

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Hussein Sabit, Ph.D

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thanks Hussein Sabit, Ph.D