This new edition of Chromosome Abnormalities and Genetic Counseling is a thoroughly updated ands richly-illustrated resource, combining basic concepts of . Medical geneticists and genetic counselors regularly see families attending the genetic counseling clinic with questions about chromosome abnormalities. PDF | On Aug 1, , Karen Brondum-Nielsen and others published Chromosome Abnormalities and Genetic Counselling.
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Chromosome abnormalities and genetic counseling Get a printable copy (PDF file) of the complete article (K), or click on a page image below to browse. PDF. Book Review. Chromosome abnormalities and genetic counseling, 3rd edn. Free resource for counselling for families with chromosome abnormalities. Chromosome Abnormalities and Genetic Counseling (Oxford Monographs on Medical Genetics): Medicine & Health Science Books.
What do I tell my patient about a referral to cardiovascular genetics? The goal of an appointment with a cardiovascular genetic counselor is to help the patient and the family with a hereditary heart condition understand what it means for each family member, both personally and medically. An appointment with a cardiovascular genetic counselor will include discussing the patient's medical and family histories. The counselor may ask questions about cardiac conditions in the family, cardiology evaluations for family members, and symptoms related to hereditary cardiac disease.
The counselor will also identify family members at risk for hereditary cardiac conditions, and discuss recommendations for medical evaluations.
A counselor can also offer support and counseling to address psychosocial issues that may arise when a genetic condition is identified in a family. Cystic Fibrosis Genetics What is cystic fibrosis genetics?
Referral to a CF genetic counselor is appropriate for a wide range of indications. Referral for preconception or prenatal genetic counseling regarding CF carrier testing is indicated for couples who are at increased risk based on family history or ethnic background.
Genetic counseling in these cases may also include discussion of prenatal testing options for CF. Families of infants with a positive newborn screen for CF are recommended to meet with a genetic counselor as part of the evaluation process.
In addition, genetic counseling can be beneficial for any patient with a known or suspected diagnosis of CF, CRMS, or another CFTR-related spectrum disorder, as well as for family members of these individuals. Identification and referral of patients who may be at risk for these conditions can come from a diverse range of specialties; for example, a male patient being evaluated for possible genetic causes of infertility may be referred to a CF genetic counselor.
Parental decision after genetic counseling for prenatal detection of sex chromosomal abnormalities
Genetic counselors interpret this information in the context of the patient's medical and family history information as well as results of various CF-related screening and diagnostic tests to provide patients with accurate risk assessment. Genetic counselors can facilitate the genetic testing process for patients and their family members.
Genetic counselors also provide psychosocial counseling to address individual issues and concerns that arise as part of this process.
CF care teams can utilize and integrate genetic counselors into their comprehensive teams. In addition to providing the services described above, genetic counselors are able to keep up to date on new mutation-specific treatments and trials that are available for CF patients such as VX, VX, etc.
All of the US states and many other countries have implemented newborn screening for CF, and most states include a DNA testing component as part of their newborn screening algorithm.
Chromosome abnormalities and genetic counseling
The implications of a positive newborn screen for CF and the issues surrounding the follow-up evaluation and diagnostic process can be complex, and genetic counselors can work with patients and their families to inform them about the significance of the newborn screen result. In addition, a positive newborn screen for CF often comes as a surprise to parents, who may have little to no prior familiarity with CF.
A CF genetic counselor is able to address the emotional and psychosocial issues that arise through this process. What evidence is there to recommend or support genetic counseling in CF genetics? A number of professional organizations have endorsed the benefit of CF genetic counseling. Farrell et al. J Pediatr. Obstet Gynecol. Research specifically related to the process of CF newborn screening has provided empiric evidence supporting the benefit of genetic counseling for families of infants with a positive newborn screen result for CF, showing that families who receive genetic counseling services demonstrate a better understanding of the implications of their child's newborn screen result than those who do not Ciske et al.
What do I tell my patient about a referral to CF genetics?
Patients referred to a CF genetic counselor can expect their appointment to include several components. The genetic counselor will obtain a detailed medical and family history, which will include targeted questions that will assist the genetic counselor in providing accurate risk assessment and counseling i. For patients interested in genetic testing for CF, the genetic counselor can provide information on the pros and cons of various testing options and will be able to facilitate the genetic testing process.
Where can I find a genetic counselor specializing in CF genetics? Fetal Intervention and Therapy FIT is a specialized area of prenatal genetics that focuses on pregnancies diagnosed with fetal anomalies. Fetal therapy refers to the diagnosis, and sometimes treatment, of fetal anomalies before birth.
Genetic counselors work as part of a multidisciplinary team in centers that provide comprehensive diagnostic services. Fetal intervention centers typically include many different and highly specialized care providers, such as fetal surgeons and maternal fetal medicine specialists.
Some centers offer fetal interventions, which can range from less invasive procedures such as amnioreductions to more invasive procedures like open fetal surgery. Who should I refer to a Fetal Intervention and Therapy genetic counselor?
Genetic counseling for sex chromosome abnormalities
Patients with pregnancies diagnosed with fetal anomalies, including: Multiple congenital anomalies Conditions for which fetal intervention may be available, such as myelomeningocele and congenital pulmonary airway malformation CPAM Conditions for which specialized care will be required at delivery, including ex utero intrapartum treatment EXIT or extra corporeal membrane oxygenation ECMO Conditions that will require care by pediatric specialists after delivery What benefit does a Fetal Intervention and Therapy genetic counselor provide to my patients?
A Fetal Intervention and Therapy genetic counselor provides a thorough assessment of the family and personal medical history. We discuss recurrence risks for future pregnancies and risks to other family members, as well as available screening options for the condition.
We also facilitate the genetic testing process, by identifying the most useful genetic test for the patient and their family.
We also assist with coordination of post-natal care and help communicate recommendations to families and healthcare providers. We work as liaisons to pediatric providers and help families bridge the gap between pre- and post-natal care.
Finally, we help patients and their families deal with the psychosocial aspects of a fetal diagnosis. We discuss pregnancy options and provide emotional support. We assist with referral to other resources, like counselors, support groups or even other families as needed.
What do I tell my patient about a referral to Fetal Intervention and Therapy genetics? We will discuss any testing options that may be available to provide more information regarding the patient's pregnancy.
We will discuss the fetal condition and review option for intervention, if available, in terms that make sense to the patient. We will also provide support and referrals to community resources as needed. Each center has their own evaluation process, so the patient may have appointments with other professionals as well.
Hematology Genetics What is hematology genetics? Hematology genetics is the study of genetic and environmental factors that influence non-malignant hematologic conditions. Some of these conditions include bleeding disorders, thrombophilias and hemoglobinopathies.
These disorders have various etiologies, disease causing mutations and inheritance patterns.
Genetic testing is available for many of the known disease causing genes, and there is ongoing research to identify additional causative or disease-modifying genes. Who should I refer to a genetic counselor that specializes in hematology? Individuals who have a diagnosis or family history of a benign hematologic condition should be referred. Referral to a hematology genetic counselor should also be considered when a patient has a known or suspected genetic condition involving hematologic disease such as Fanconi anemia, Hermansky-Pudlak syndrome or thrombocytopenia absent radius TAR syndrome.
Patients will benefit from genetic services throughout the many stages of their life i.
What evidence is there to recommend or support genetic counseling in hematology genetics? The American College of Medical Genetics has issued guidelines for Factor V Leiden and prothrombin GA testing, which include the use of genetic counselors for result interpretation and communication with the patient.
In addition, the use of genetic counseling in thrombophilia care is discussed in articles by Varga , E. What do I tell my patient about a referral to hematology genetics what to expect during the appointment, what questions will be asked, what topics will be discussed, how the appointment will be valuable to them?
Genetic counseling appointments are tailored to each patient's reason for referral and questions.
In general, your patient's medical and family histories will be obtained and available testing results will be reviewed. The patient's genetic diagnosis, the inheritance pattern of the disease and risks to other family members will be discussed in detail. Psychosocial issues and reproductive options will also be discussed, particularly if your patient is interested. The goal of the appointment is to provide your patient with information that is accurate, concise and easy to understand.
Patients who meet with a genetic counselor have a unique opportunity to receive ongoing support, information and continuity of care all of which provide a solid foundation for personalized and informed decision making. We detected 74 abnormal karyotypes 8.
When obtaining amniotic fluid or chorionic villus samples was difficult, alternative fetal materials urine, cystic hygroma, cystic lung, intreperitoneal and cerebrospinal fluids were collected and we had success in obtaining karyotypes in all 13 cases.
Although, the option of terminating abnormal pregnancies does not legally exist in Brazil, the information gained in assessing the prognosis of on-going pregnancies or estimating recurrence risks justifies prenatal diagnosis of chromosome abnormalities. We conclude that, in keeping with the policy in most other countries, prenatal cytogenetic analysis is strongly recommended in high-risk pregnancies for fetal abnormalities.
However, the unique aspect of this type of study is not its rarity in world terms, but its rarity in Brazil. This argues that Brazilian health policy on prenatal diagnosis requires reforming to make it much more widely available within the public health care sector.
Key words: prenatal diagnosis, chromosomal abnormalities, fetal malformations.
Invasive prenatal diagnosis continues to be the standard method for searching for chromosomal aneuploidies or other genetic diseases Bui, Prenatal diagnosis of cytogenetic abnormalities is now widely recognized as a reliable method with an acceptable risk for couples at high risk of giving birth to a child with clinically significant chromosome abnormalities Caron et al.
As in other developing countries, this test is mostly confined to expensive private clinics, which means that it is rarely available for the great majority of pregnant women who depend on public medical services. Nevertheless, we have been offering this test in our public hospital since Prenatal diagnosis is a very restricted test in Brazil, mainly because induced abortion, even indicated by fetal genetic disease, is not legally allowed. Despite this, we have had referrals for fetal karyotyping since it was first offered by our clinic in This will be discussed later.
Even with the development of modern techniques, cell culture failure remains one of the main obstacles to be overcome.
In order to improve the chance of getting a karyotype result, alternative fetal samples, such as urine or cystic hygroma fluid were used for chromosome analysis when malformations were found in the fetus and availability of conventional tissues was limited. The purposes of this study were: 1 to describe the most frequent indications for karyotyping the fetus in our socio-economic conditions; 2 to estimate the frequency of the most common prenatal chromosome abnormalities in patients from the Hospital de Clinicas de Porto Alegre; 3 to assess the cytogenetic results obtained with alternative tissue samples compared to amniocytes and chorionic villi.
Materials and Methods Cytogenetic findings were retrospectively reviewed from to in pregnant women, with a mean maternal age of Those women underwent prenatal cytogenetic evaluation only after a genetic counseling session, which means that risks, methods and indications were explained to the family.
All samples were collected by a single gynecologist. The method used for sample collection was transabdominal punction guided by ultrasound. Samples were obtained for all patients, even in cases of lack of amniotic fluid, when alternative fluids were collected.
We used standard Giemsa-banding staining technique for all chromosome analyses. Results The most frequent indications for prenatal cytogenetic diagnosis were advanced maternal age with an average of Despite advanced maternal age being the most frequent indication for prenatal diagnosis, the majority of aberrant karyotypes were found when the indication was a fetal malformation detected by ultrasound. On the other hand, although the history of a previous child with Down syndrome was a relatively frequent indication, we did not find any positive cases in this group.
From the prenatal cytogenetic analysis performed, we failed to obtain results in 26 2.
Among the karyotypes obtained, 74 8. Numerical abnormalities were found in 64 cases 7. The majority of numerical chromosomal abnormalities were autosomal trisomies. Trisomy 21 was the most frequent 28; 3. Trisomy 13 was found in six cases 0. Among structural chromosomal aberrations, translocations were the most frequent, and were detected in four out of the cases analyzed 0. Marker chromosomes were found in three cases, deletions in two cases and an inversion was present in one case.
In 13 cases alternative fluid samples were obtained Table 2. The gestational age varied from 18th to 36th weeks with a mean age of We had success in culturing these materials and in obtaining karyotypes in all cases Table 2.
Discussion Prenatal diagnosis has become a major aid to genetic counseling and for this, several important areas of technology have evolved, especially cytogenetic prenatal diagnosis, using analysis of cultured cells from the amniotic fluid at mid-trimester.
Because of its high reliability and safety record with the lowest fetal loss and embryonic damage, amniocentesis has become the most common practice for prenatal diagnosis Park et al. However, CVS chorionic villus sample has gained popularity as a successful first trimester prenatal diagnostic technique since the mid s Brambati et al.
Cordocentesis is a procedure used to obtain a sample from fetal blood directly from the umbilical cord in cases where amniocentesis is not possible or is used to give a quick result only in high-risk cases since procedure related pregnancy loss is high Costa et al.
Prenatal cytogenetic diagnosis using the above techniques was established in many countries, including Brazil Gollop et al. On the other hand, when other forms of fetal abnormality detected by ultrasound were considered, then a frequency of trisomy 18 emerged which was even higher than trisomy 21 within this group. Intriguingly, our results suggest that prior diagnosis of fetal malformations using ultrasound is particularly efficacious for detecting trisomy 21 with the nuchal translucency test and, for trisomy 18, when other types of malformation are detected.
However, Cheng et al.Neuroscientific Techniques.
We used standard Giemsa-banding staining technique for all chromosome analyses. Genetic counselors interpret this information in the context of the patient's medical and family history information as well as results of various CF-related screening and diagnostic tests to provide patients with accurate risk assessment. Sign in to annotate. Critical Care Surgery. Physicians and health providers from various specialties are encountering diagnoses of SCAs with increased frequency as more individuals are becoming identified, both prenatally and postnatally.
The results on chromosomal abnormalities in RPL provide information regarding the role of chromosomal anomalies in RPL and also the usefulness of cytogenetic investigation to rule out the possible genetic cause of recurrent pregnancy loss. Journal of Genetic Counseling, 2 3 : Clinical Genetics.