NCMA 219 (Week 1) PDF - Genetic Assessment and Counseling

Genetic assessment and counselling​ Content ​ Definition, Purpose, types and basis of genetic testing ​ Prenatal diagnosis and screening ​ Common diagnosis test ​ Techniques for pathological examination ​ Ethical legal and psychosocial issue in genetic testing Reason for genetic testing...

Genetic assessment and counselling​ Content ​ Definition, Purpose, types and basis of genetic testing ​ Prenatal diagnosis and screening ​ Common diagnosis test ​ Techniques for pathological examination ​ Ethical legal and psychosocial issue in genetic testing Reason for genetic testing ​ Finding genetic disease in unborn child ​ Finding out if people carry genes for disease and might pass it on to their children. ​ Screening embryos for disease ​ Testing for genetic disease in adults before they cause symptoms. ​ Making a diagnosis in a person who has disease symptoms. ​ Figuring out the type or dose of a medicine that is best for a certain person Definition DEFINITION ​ Genetic testing is defined as “examining a ​ The American Society of Human sample of blood or other fluids or tissue Genetics defines Genetic counseling as a for bio-chemical chromosomal, or genetic communication process, which deals with markers that indicate the presence or human problems associated with the absence of genetic disease. occurrence or the risk of occurrence of a ​ A genetic testing is an analysis of DNA genetic disorder in a family. to look for genetic alteration that may ​ Smith (1955) defines counseling as "a indicate an increased risk for developing a process in which the counselor assists the specific disease or disorder OR it is also counselee to make interpretations of facts defined as a type of medical test, relating to a choice, plan or adjustments identifying changes in chromosomes, which he needs to make. genes or proteins. ​ Genetic counseling is a communication process by which personal genetic risk INTRODUCTION information is translated into practical Genetics: branch of biology concerned with information for families. the study of genes, genetic variations, and ​ It is defined as a process in which patients heredity in living organisms. or their relatives at the risk of a genetic Counseling: is a process of communicating bt. 2 disorder are made aware of the or more persons who meet to solve a problem, consequences of the disorder, its resources a curse or take decision on various transmission and the ways by which this matters. It is not a one way process where in the can be prevented or mitigated. counselling tells the client what to do nor it is a forum for presenting of the counselor’s value Purpose of genetic counselling Genetic counseling: 1. Pedigree : Pedigrees are family trees which ​ Genetic counseling is the process of show the parents and offspring across advising individuals and families affected generations, as well as who possessed particular by or at risk of genetic disorders to help traits. Pedigrees of individual families are used by them understand and adapt to the genetic counselors, to aid them in providing medical, psychological and familial information to families who may be at risk for implications of genetic contributions to various genetic conditions. disease. 2. Ethnicity: In obtaining a family history, a ​ Sheldon Reed proposed the terminology genetic counselor asks about a person's ethnicity "Genetic Counseling" in 1947 or ancestral origin. There are some ethnic groups that have a higher chance of being carriers of some genetic disease or abnormalities. For example, the chance that an African American is a carrier of a gene for sickle cell disease is one in Pedigree Charting ten. At a glance this offers in a concise manner the 3. Consanguinity: Another question counselor state of disorder in a family. Constructing a will ask is about obtaining a family history pedigree with proper interrogation though time whether the couple are related to one another by consuming, is ultimately rewarding. If forms an blood. Because it will increase the chance for their indispensable step towards counseling children to be affected with conditions that are in Estimation of Risk: a recessive pattern ​ It forms one of the most important aspects 4. Exposure during pregnancy: Counselor of genetic counseling. It is often called will ask about the pregnancy history. If a women recurrence risk. To estimate it one has taken medications or has had exposure to a requires to take into account following potentially harmful substance from the points environment such as chemical and toxins etc., the Mode of inheritance: genetic counselor can discuss about possibility of ​ Analysis of pedigree or family tree adverse effects ​ results of various tests INDICATIONS ​ If a standard prenatal screening test Transmitting Information (such as a fetoprotein test) yields an ​ After completing the diagnosis, pedigree abnormal result. charging and estimation of risk the next ​ An amniocentesis yields unexpected most important step is communicating results (such as chromosomal defect in the this information to the consultants. unborn baby). ​ This important functioning involves ​ Either parent or close relative has an various factors such as Psychology of the inheritance disease or birth defect, either patient. parents already have children with birth ​ Emotional stress under prevailing defect or genetic disorders. circumstances. ​ The mother has had two or more ​ Attitude of family members towards the miscarriage or a baby dies in infancy. patients. ​ The mother is 35 yrs of age or over. ​ Educational, social and financial ​ The partner is blood relatives background of the family. ​ Gaining confidence of consultants in STEPS OF GENETIC COUNSELING subsequent meetings during follow up. To complete an accurate diagnosis the following ​ Ethical, moral and legal implications procedure should be followed: involved in the process. ​ History: ​ Above all, communication skills to ​ A proper record of the history of the transmit facts in an effective manner i.e. patient is necessary: This includes both making them more acceptable and present and relevant past history, Family palatable. history includes siblings and other Management: relatives also. ​ In genetics, "Treatment" implies a very ​ Kindly note if there is any other person in limited scope. It naturally aims for the family with a similar problem prevention rather than cure. In fact for ​ Obstetric history includes exposure to most of the genetic disorders the cure is teratogens (drugs, X-rays) in pregnancy. unknown. Treatment is therefore directed History of abortion or stillbirth if any, towards minimizing the damage by early should be recorded detection and preventing further ​ Enquiry should be made about irreversible damage. For example in PKU, consanguinity as it increases the risk i.e. phenylketonuria. This disorder is especially in autosomal recessive disorders characterized by a deficiency of phenylalanine hydroxylase enzyme, which is necessary for the conversion of phenylalanine to tyrosine. TYPES OF GENETIC COUNSELLING ​ The developing embryo can first be ​ Prospective: wider application to cover a visualized at about 6 weeks gestation. number of recessive defects. It identifies ​ Recognition of the major internal organs the individuals for any particular defect by and extremities to determine if any screening (Counseling given before the birth of an affected child or before conception.) abnormality can best be accomplished For example: sickle cell anemia which can be between 16 to 20 weeks gestation. prevented. ​ the size and position of the fetus, the size ​ Retrospective: this can be done after and position of the placenta, the amount contraception, pregnancy termination and of amniotic fluid, the appearance of fetal sterilization. Counseling given after the birth of a anatomy. child with a genetic disorder. APPLICATIONS OF GENETIC LIMITATION OF USG COUNSELING Abnormalities may not be detected until later in ​ Genetic counselors work with people pregnancy, or may not be detected at all. concerned about the risk of an inherited A good example of this is Down syndrome disease or condition. These people (trisomy 21) where the morphologic abnormalities represent several different populations are often not marked, Prenatal Genetic Counseling AMNIOCENTESIS ​ There are several different reasons a This is an invasive procedure. person or couple may seek prenatal Amniocentesis weeks gestation. are performed genetic counseling. If a woman is of age 35 between 14 and 20 or older and pregnant, then there is an An ultrasound amniocentesis examination increased chance that her fetus may have a always precedes change in the number of chromosomes In the third trimester of pregnancy, the amniotic present. Changes in chromosome number fluid can be analyzed for determination of fetal may lead to mental retardation and birth lung maturity defects. amniotic fluid can be analyzed for lecithin:sphingomyelin (LS) ratio, and/or for TYPES OF GENETIC TESTING phosphatidyl glycerol (PG). BASIS OF GENETIC TESTING fetal loss (0.5%) ​ Quantitative genetic research has built a maternal Rh sensitization. strong case for the importance of genetic If oligohydramnios is present, then amniotic factors in many complex behavioural fluid cannot be obtained. disorders and dimensions in the domains of psychopathology, personality and CHORIONIC VILLI SAMPLING: cognitive abilities. CVS can be safely performed between 9.5 and ​ The genetic basis of behavioural disorder 12.5 weeks gestation. has largely relied on a reductionist one In this procedure, a catheter is passed via the gene one disorder (ONOD) approach in vagina through the cervix and into the uterus to which a single gene is necessary and the developing placenta under ultrasound sufficient to develop a disorder. In guidance contrast a quantitative trait loci approach The introduction of the catheter allows sampling involves the search for multiple genes. of cells from the placental chorionic villi. Prenatal tests These cells can then be analyzed by a variety of ​ Level II Ultrasound techniques. The most common test employed on ​ The maternal serum AFP cells obtained by CVs is chromosome analysis to ​ Chorionic Villus sampling (CVS) determine the karyotype of the fetus. ​ Amniocentesis ULTRASONOGRAPHY ​ This is a non-invasive procedure that is harmless to both the fetus and the mother. MATERNAL BLOOD SAMPLING FOR The HCG level can be used to follow up FETAL CELLS treatment for molar pregnancy to make sure that This is a new technique that makes use of the no trophoblastic disease, such as a phenomenon of fetal blood cells gaining access to choriocarcinoma, persists. maternal circulation through the placental villi. The fetal cells can be sorted out and analyzed by MATERNAL SERUM ESTRIOL a variety of techniques to look for particular DNA ​ The amount of estriol in maternal serum is sequences dependent upon a viable fetus, a properly Fluorescence in-situ hybridization (FISH) functioning placenta, and maternal is one technique that can be applied to identify well-being. >>>>|| particular chromosomes of the fetal cells ​ substrate for estriol begins as recovered from maternal blood and diagnose dehydroepiandrosterone (DHEA) made by aneuploid conditions such as the trisomies and the fetal adrenal glands>>>|| monosomy X. ​ This is further metabolized in the placenta PROBLEMS to estriol. >>>>|| It is difficult to get many fetal blood cells. ​ The estriol crosses to the maternal There may not be enough anomalies of the fetal circulation and is excreted by the maternal karyotype abnormalities. kidney in urine or by the maternal liver in the bile MATERNAL SERUM ALPHA FETOPROTEIN The measurement of serial estriol levels in the The developing fetus has two major blood third trimester will give an indication of general proteins- albumin and alpha-fetoprotein (AFP). well-being of the fetus The MSAFP test can be utilized to determine the If the estriol level drops, then the fetus is levels of AFP from the fetus threatened and delivery may be necessary Ordinarily, only a small amount of AFP gains emergently access to the amniotic fluid and crosses the Estriol tends to be lower when Down syndrome placenta to mother's blood is present and when there is adrenal hypoplasia When there is a neural tube defect in the fetus, with anencephaly. Then there is a means for escape of more AFP into the amniotic fluid. INHIBIN-A The AFP from the fetus will end up in maternal ​ Inhibin is secreted by the placenta and the blood in higher amounts. without parts of the corpus luteum. brain and skull. Neural tube defects include anencephaly and ​ Inhibin -A is associated with an increased spina bifida spinal column does not close completely, leaving risk of trisomy 21, the spinal cord exposed or unprotected. ​ A high inhibin -A may be associated with MATERNAL SERUM BETA-HCG a risk for preterm delivery. This test is most commonly used as a test for A low inhibin -A May indicate Trisomy 18 (Edwards syndrome) or poor placental function. pregnancy. PREGNANCY-ASSOCIATED PLASMA The beta-HCG can also be quantified in serum PROTEIN A (PAPP-A) from maternal blood, and this can be useful early ​ Low levels of PAPP-A as measured in in pregnancy when threatened abortion or ectopic maternal serum during the first trimester pregnancy suspected may be associated with fetal chromosomal because the amount of beta-HCG will be lower anomalies including trisomies 13, 18, and than expected 21 An elevated beta-HCG coupled with a decreased ​ Low PAPP-A levels in the first trimester MSAFP suggests Down syndrome. may predict an adverse pregnancy Very high levels of HCG suggest trophoblastic outcome, including a small gestational age disease (molar pregnancy). (SGA) baby or stillbirth. The absence of a fetus on ultrasonography along ​ A high PAPP-A level may predict a large with an elevated HCG suggests a hydatidiform gestational age (LGA) baby. mole  "TRIPLE" OR "QUADRUPLE" SCREEN MICROBIOLOGIC CULTURE Combining the maternal serum assays may aid Culture can aid in diagnosis or confirmation of in increasing the sensitivity and specificity of congenital infections:- detection for fetal abnormalities. T-toxoplasmosis The classic test is the triple screen for O - other, such as Listeria monocytogenes, group alpha-fetoprotein (MSAFP), beta-HCG, and B streptococcus, syphilis estriol (uE3). The "quadruple screen" adds R-rubella inhibin-A. C- cytomegalovirus H - herpes simplex or human immunodeficiency TECHNIQUES FOR PATHOLOGIC virus (HIV) EXAMINATION GROSS EXAMINATION: KARYOTYPING It is useful in detecting gross fetal parts. Tissues must be obtained as fresh as possible for The pattern of gross abnormalities can often culture and without contamination. suggest a possible chromosomal abnormality or a A useful procedure is to wash the tissue samples syndrome. in sterile saline prior to placing them into cell Consultations are obtained with clinical culture media. geneticists to review the findings Tissues with the best culture for growth are those Examination of the placenta is very important, with the least maceration: placenta, lung, and because the reason for the fetal loss may be a diaphragm. placental problem Obtaining tissue from more than one site can MICROSCOPIC EXAMINATION increase the yield by avoiding contamination or Microscopic examination of the placenta is by detection of mosaicism. important Microscopy can aid in determination of ETHICAL, LEGAL AND PSYCHOSOCIAL gestational age (lung, kidney maturity), presence ISSUES of infection, presence of neoplasia, or presence of "dysplasia" (abnormal organoon CONSENT TO BEING SCREENED:- Patients need to be sufficiently informed about RADIOGRAPHY: the implication of genetic screening before they Radiographic views are essential for analysis of can provide informed consent. the fetal skeleton. The public views genetics with a sense of Radiographs are useful for comparison with inevitability. However, a genetic condition alone prenatal ultrasound, and help define anomalies may modify risks from environmental or lifestyle when autopsy consent is limited factors. To determine sites to be examined The voluntary nature of the screening process microscopically. must be emphasized. Conditions diagnosed by postmortem COUNSELING radiography may include: abnormal cell growth or development To reduce potential psychological distress, Skeletal anomalies (dwarfism, dysplasia, etc.) counseling should be available to provide Neural tube defects (anencephaly, spina bifida, information about genetic risk and explain etc.) choices regarding genetic testing and further Osteogenesis imperfecta (brittle bones that fracture easily) management. Soft tissue changes (hydrops, hygroma, c.) Support is needed for individuals who need to Teratomas or other neoplasms consider issues such as stigma disclosure to Growth retardation (Delayed fetal or child development) family members and confidentiality. Orientation and audit of fetal parts Assessment of catheter or therapeutic device Couples known to carry a recessive or dominant placement single gene defect or sex linked condition need Hydrops (Hydrops Fetalis) - Severe fluid buildup in a fetus (skin, lungs, heart, or abdomen) counseling about their reproductive option. This Hygroma (Cystic Hygroma) - A fluid-filled sac (usually in the neck) may include prenatal diagnosis and possible Teratomas - Tumors with various tissue types, commonly seen in newborns. Neoplasms - Abnormal tissue growths, which can be benign (non-cancerous) or malignant (cancerous). pregnancy termination in the case of an affected out an insurance policy without disclosing this fetus and pre-implantation genetic diagnosis. information. THE RISK OF STIGMA:- Pediatric Genetic Counseling The public's understanding of genetics may be ​ Families or pediatricians seek genetic limited and can lead to sigma. counseling when a child has features of an Misunderstanding of the genetic risk of inherited condition. Any child who is born developing disease can increase stigmatization. with more than one defect, mental This may be around life expectancy, lifestyle retardation or dysmorphic features has an choices, or decisions about having children. increased chance of having a genetic Identification of a genetic condition before birth syndrome. A common type of mental raises the issue of whether the parents wish to retardation in males for which genetic terminate the pregnancy. Some commentators testing is available is fragile X-syndrome. have argued that the ability to only select perfect babies is a form of eugenics. Adult Genetic Counseling Confidentiality ​ Adults may seek genetic counseling when Like other medical information, results from a person in the family decided to be tested genetic testing are considered confidential, under for the presence of a known genetic normal practice, the doctor patient relationship condition, when an adult begins exhibiting protects against disclosure of genetic information. symptoms of an inherited condition, or However there is less clarity where relatives wish when there is a new diagnosis of someone to know the result of a family member's genetic with an adult-onset disorder in the family test, as it may have direct relevance for them. ​ In addition, the birth of a child with Another particular dilemma is the case of a obvious features of a genetic disease leads pregnant woman wanting to know the result of a to diagnosis of a parent who is more test taken by the baby's father. mildly affected. The storage of genetic screening data and ​ Genetic counseling for adults may lead to registries of patients creates particular concern, the consideration of presymptomatic given that the results may impact negatively on genetic testing family members. Cancer Genetic Counseling DISCLOSURE TO FAMILY MEMBERS:- ​ A family history of early onset breast, Doctors face a dilemma when reporting the ovarian or colon cancer in multiple results of genetic screening. Standard medical generations of family is a common reason practice is based on the principles that doctor's a person would seek a genetic counselor should focus on their patient and that medical who works with people who have cancer. information should remain confidential. ​ While most cancer is not inherited, there It is unclear if doctors are ethically permitted to are some families in which a dominant inform relatives in cases when the result of gene is present and causing the disease genetic test indicates real risk to their health. ​ A genetic counselor is able to discuss the Doctors may also be faced with a decision about chances that the cancer in the family is whether to persuade patients about the need to related to a dominantly inherited gene. disclose their test result to relatives. ​ The counselor can also discuss the option Although most professional bodies that disclose of testing for the breast and ovarian cancer should not be against the right of relatives to have genes won priorities. The primary concerns among the public is the IN SHORT GENETIC COUNSELLING IS use of genetic information to delay access to ​ Determine the facts: Diagnosis, health insurance or medical treatment. etiology, and inheritance patterns, Conversely health insurance claims the right to prognosis, natural history, treatment and access such data where it exists to avoid the moral re- occurrence of risk. hazards of patients with known conditions taking  ​ Transmitting the information: To REPUBLIC ACT9262: ANTI- VIOLENCE those requesting it in a sensitive, culturally AGAINST WOMEN AND THEIR appropriate, understandable way. CHILDREN ​ Supporting the decision: Supporting Refers to any act or a series of acts committed by the decision making process of the couple. an intimate partner ​ Genetic counselling: It is non-directive. Against a woman who is his wife, former wife Against a woman with whom the person has or CODE OF ETHICS had sexual or dating relationship ​ The National Society of Genetic Against a woman with whom he has a common Counselors has created a code of ethics to child guide genetic counselors in caring for Against her child whether legitimate or people. illegitimate within or without the family abode ​ Beneficence: Do good. Always act in a way that helps others and promotes their Types of Abuse: well-being. Physical violence ​ Non-maleficence: Do no harm. Avoid Sexual violence causing harm to others, whether by Psychological violence actions or decisions. Economic abuse ​ Autonomy: Respect people’s right to make their own choices about their life Protection Order and body. Barangay Protection Orders (BPO ​ Justice: Be fair. Treat everyone equally Temporary Protection Orders (ΤΡΟ) and make sure resources or opportunities Permanent Protection Order (PPO) are distributed fairly. ​ Non-directive counseling: Provide Intimate Partner Abuse information and support without telling Abuse by a family member against another adult someone what to do. Let them decide for living in the household themselves. Common injuries suffered by abused women: Burns ETHICAL ISSUES Lacerations ​ Access to PND services Bruises ​ Research on PND Head injuries ​ Ethical issues Abused women may: ​ Abortion choices Have unintended and unwanted pregnancy Desire pregnancy because she believes having a ROLE OF A NURSE IN GENETIC child will change the partner's behavior COUNSELING Be grateful for the pregnancy ​ Guiding a woman or couple through prenatal diagnosis. Behaviors of abused women: ​ Helping parents make decisions in regard May come for care late in pregnancy or not at all to abnormal prenatal diagnostic results. Purchase no maternity clothing ​ Assisting parents who have had a child Decline laboratory tests if they involve with a birth defect to locate needed service additional transportation or money and support. Difficulty following recommended pregnancy ​ Providing support to help the family deal nutrition with the emotional impact of a birth Anxious if her appointment is running late defect. Call and cancel appointments frequently ​ Coordinative services of other Dress inappropriately for warm weather, professionals, such as social workers, wearing long-sleeved, tight-necked blouses to physical and occupational therapist, cover up bruises psychologist & dietician. Assessment: Ancestor A known common ancestor between Presence of bruises or lacerations on breasts, the parents sometimes exists. This explains how abdomen, or back she cannot explain during both male and came to possess a like gene for the physical examination disorder Ask woman with bruises to account for them and determine whether explanation correlates X-LINKED DOMINANT INHERITANCE with the extent and placement of bruise or affects both males and females, but usually more severe in males. laceration Dominant gene All individuals with the gene Ultrasound may reveal minimal placental are affected infarcts from blunt abdominal trauma Affected All female children of affected men are Record fetal heart tones and fundal height affected; all male children of affected men are unaffected Nursing interventions: Generation It appears in every generation Support any ability the woman had to make Homozygous/ Heterozygous All children of constructive decisions homozygous affected women are affected. Fifty Discuss how she can call the police any time and percent of the children of heterozygous affected take her to shelter women are affected Help to file charges or obtain restraining order to Males Only males in the family will have the keep the abusive person from coming near the disorder woman if necessary History of death A history of girls dying at Be careful not to blame the victim birth for unknown reasons often exists (females Help find a shelter where the woman will feel who had the affected gene on both X safe chromosomes). Do not leave an abused woman without support Unaffected Sons of an affected man are system after the birth of her child unaffected Parents The parents of affected children do not GENETIC ASSESSMENT AND have the disorder COUNSELLING MULTIFACTORIAL (POLYGENIC) INHERITANCE Disorders influenced by multiple genes and environmental factors. GENETIC DISORDERS ​ NATURE OF INHERITANCE MANY CHILDHOOD DISORDERS TEND TO ​ MENDELIAN INHERITANCE HAVE HIGHER-THAN USUAL INCIDENCE ​ DOMINANT PATTERN OCCUR FROM MULTIPLE GENE ​ RECESSIVE PATTERNS COMBINATIONS POSSIBLY COMBINED WITH ​ INHERITANCE OF DISEASE ENVIRONMENTAL FACTORS DO NOT FOLLOW THE MENDELIAN LAWS AUTOSOMAL DOMINANT DISORDERS NO SET PATTERNS IN FAMILY HISTORY One Parent - One of the parents of a child with the disorder also will have the disorder IMPRINTING Sex - The sex of the affected individual is REFERS TO THE DIFFERENTIAL unimportant in terms of inheritance. EXPRESSION OF GENETIC MATERIAL History - There is usually a history of the A genetic phenomenon where only one copy of a gene (either from mother or father) is active, and the other is "silenced." disorder in other family members ALLOWS RESEARCHERS TO IDENTIFY WHETHER CHROMOSOMAL MATERIAL AUTOSOMAL RECESSIVE INHERITANCE COMES FROM THE MALE OR FEMALE Both Parent Both parents of a child with the PARENT disorder are clinically free of the disorder. CHROMOSOMAL ABNORMALITIES Sex The sex of the affected individual is (CYTOGENETIC DISORDERS) unimportant in terms of inheritance. History The family history for the disorder is NONDISJUNCTION ABNORMALITIES negative-that is, no one can identify anyone else ​ ABNORMALITIES OCCUR IF THE who had it (a horizontal transmission pattern). DIVISION IS UNEVEN Errors in chromosome separation during cell division, leading to extra or missing chromosomes (e.g., Down syndrome).  ​ IF SPERMATOZOON OR OVUM WITH ​ ALLOW PEOPLE WHO ARE AFFECTED 24 OR 22 CHROMOSOMES FUSES WITH BY INHERITED DISORDERS TO MAKE A NORMAL SPERMATOZOA OR OVUM. INFORMED CHOICE ABOUT FUTURE THE ZYGOTE WILL HAVE EITHER 47 REPRODUCTION OR 45 CHROMOSOMES, NOT THE ​ OFFER SUPPORT TO PEOPLE WHO NORMAL 46 ARE AFFECTED BY GENETIC ​ 45 CHROMOSOMES IS NOT DISORDERS COMPATIBLE WITH LIFE AND COULD WHO SHOULD GO FOR GENETIC LEAD TO ABORTION. COUNSELLING? ​ COUPLE WHO HAS A CHILD WITH DELETION ABNORMALITIES CONGENITAL DISORDER OR AN ​ PART OF THE CHROMOSOMES INBORN ERROR OF METABOLISM BREAKS DURING CELL DIVISION ​ COUPLE WHOSE CLOSE RELATIVES CAUSING THE AFFECTED PERSON TO HAVE A CHILD WITH A GENETIC HAVE AN EXTRA PORTION OF A DISORDER CHROMOSOME. ​ ANY INDIVIDUAL WHO IS KNOWN BALANCED TRANSLOCATION CARRIER TRANSLOCATION ABNORMALITIES ​ ANY INDIVIDUAL WHO HAS AN ​ A CHILD GAINS ADDITIONAL INBORN ERROR OF METABOLISM OR CHROMOSOME THROUGH ANOTHER CHROMOSOMAL DISORDER ROUTE. ​ A CONSANGUINEOUS (CLOSELY RELATED) COUPLE ISOCHROMOSOMES ​ ANY WOMAN OLDER THAN 35 YEARS ​ RESULTS FROM CHROMOSOME AND ANY MAN OLDER THAN 55 YEARS ACCIDENTALLY DIVIDING NOT BY ​ COUPLES OF ETHNIC BACKGROUNDS VERTICAL SEPARATION BUT BY IN WHICH SPECIFIC ILLNESSES ARE HORIZONTAL ONE SO A NEW KNOWN TO OCCUR. CHROMOSOME WITH MISMATCHED LONG AND SHORT ARMS NURSING RESPONSIBILITIES EXPLAIN WHAT PROCEDURES TO some cells have a normal chromosome MOSAICISM number, while others have an abnormal one UNDERGO ​ ABNORMAL CONDITION THAT IS EXPLAIN HOW DIFFERENT GENETIC PRESENT WHEN THE SCREENING WHEN OFFERED TESTS ARE NONDISJUNCTION DISORDER DONE AND OCCURS AFTER FERTILIZATION OF SUPPORT THE COUPLE DURING THE WAIT THE OVUM AS THE STRUCTURE FOR TEST RESULTS BEGINS MITOTIC DIVISION. ASSIST COUPLES IN VALUES ​ DIFFERENT CELLS IN THE BODY WILL CLARIFICATION, PLANNING, AND DECISION HAVE DIFFERENT CHROMOSOME MAKING BASED ON TEST RESULTS COUNTS GENETIC DISORDERS ASSESSMENT GENETIC COUNSELLING History ​ PROVIDE CONCRETE, ACCURATE Physical assessment Diagnostic INFORMATION ABOUT THE PROCESS testing OF INHERITANCE AND INHERITED ​ Karyotyping DISORDERS ​ Maternal serum screening ​ Chorionic villi sampling ​ REASSURE PEOPLE WHO ARE ​ Amniocentesis CONCERNED THAT THEIR CHILD MAY ​ Percutaneous umbilical blood sampling INHERIT A PARTICULAR DISORDER ​ Fetal imaging OR THAT THE DISORDER WILL NOT ​ Fetoscopy OCCUR ​ Preimplantation diagnosis