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Genetics for Maternal Child Health Nursing

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Presentation on theme: "Genetics for Maternal Child Health Nursing"— Presentation transcript:

1 Genetics for Maternal Child Health Nursing
Brandy M. Freschi (Smolnik), MS, CGC Certified Genetic Counselor Perinatal Associates of Northern Nevada Ph Fax

2 Overview Genetic Counselors & Genetic Counseling Prenatal Genetics
Neonatal & Pediatric Genetics Pregnancy Loss Grief/Bereavement

3 Genetic Counselors Genetic counselors are health professionals with specialized Master’s degrees and experience in the areas of medical genetics and counseling. Accredited by the American Board of Genetic Counseling; require specific competencies, case load/type, and coursework Board certification required; Licensure available in only some states Genetic counselors work as members of a health care team, who provide information and support to families who have members with or are at risk for birth defects and/or genetic/inherited disorders by: Identify families at risk Investigate the problem present in the family Interpret information about the disorder Analyze inheritance patterns and risks of recurrence Review available testing and treatment options with the family Genetic counselors also: Provide supportive counseling to families Serve as patient advocates Refer individuals and families to community or state support services. They serve as educators and resource people for other health care professionals and for the general public Settings: Prenatal, Pediatric/Adult, Cancer, Laboratory, Research, Specialty Disease Clinics, etc. Non-directiveness Unique from other disciplines/settings in health care Important because genetics often involves reproductive decisions which are made involving many factors: Magnitude of risk Burden of impact of disorder Individual perception of impact Meaning of children Individual cultural, religious or personal preferences

4 Why is Genetics Important in Maternal Child Health Nursing?
Incidence of chromosome abnormalities - 1/200 40-60% of admissions to children hospitals are for genetic or genetic related conditions Thousands of genetic conditions exist with new ones discovered regularly Majority of all deaths have a genetic component

5 Prenatal Genetics

6 Indications for a Genetic Counseling Referral
FINDING Increased risk for aneuploidy AMA (35-singleton; 33-twins) Positive serum screen Abnormal ultrasound marker/finding Family history chromosome abnormality REASON TO CONSIDER CONSULTATION Discuss risks to pregnancy and available testing options CVS Amniocentesis 1st or 2nd tri screening Level II ultrasound

7 Aneuploidy Definition: Most common type of chromosome abnormality
The occurrence of one or more extra or missing chromosomes leading to an unbalanced chromosome complement, or, any chromosome number that is not an exact multiple of the haploid number Most common type of chromosome abnormality Examples: Trisomy: one extra chromosome for a total of 47 Monosomy: one missing chromosome for a total of 45 Typically not inherited, most trisomies occur due to nondisjunction


9 Case #1 37 y, G4P3 Referred for advanced maternal age (AMA) and first trimester screening Ultrasound at initial visit revealed fetus had increased nuchal translucency (3.6 mm) Pt declined FTS and CVS; elected to proceed with amniocentesis after 16 weeks Results were consistent with trisomy 21 (Down syndrome)

10 Case #1 Trisomy 21: Down syndrome
Most common aneuploidy, 1/800 births Mental retardation: Typically mild to moderate but encompasses full range of ability-disability Characteristic facial features Hypotonia Feeding and breathing difficulties Congenital heart defects: 50% of all affected individuals Typically AV canal defects Trisomy 21 is not inherited, due to nondisjunction which is a risk for each and every pregnancy at any maternal age Average life span 50-60 Vision problems Small head Hypothyroidism Duodenal atresia Tracheoesophageal fistula 10

11 Nuchal translucency Normal translucency Increased nuchal translucency

12 Down syndrome (Trisomy 21)

13 Case #2 34 y o, G1P0 Referred due to abnormal ultrasound findings: choroid plexus cysts, clenched hands, and possible heart defect Findings above were confirmed also IUGR was noted Patient was counseled on increase risk for chromosome aneuploidy Amniocentesis performed and karyotype revealed trisomy 18 (Edwards syndrome) ama 13

14 Case #2 Trisomy 18: Edwards Syndrome
1/3000 births IUGR Brain abnormalities Hypotonia Seizures CPCs Heart defects Renal abnormalities Dysmorphic features: Short palpebral fissures Micrognathia Low set ears Clenched fists Cleft lip/palate Rocker-bottom feet Hearing loss Feeding and breathing difficulties High mortality rate: 90% are miscarried or stillborn; 90% die within first year of life (most within the first few days) Lack of characteristic facial appearance 90% die within first year of life 14


16 Trisomy 18

17 Case #3 27 y o, G4P2 Referred for first trimester screening
Ultrasound revealed a cystic hygroma Pt declined screening and opted for CVS Results were 45,X or Turner syndrome

18 Case #3 45, X: Turner syndrome
Case #3 45, X: Turner syndrome 1/2,500 births Heart defects Coarctation of the aorta Short, webbed neck Low set ears Swollen hands and feet Not associated with MR but may specific learning issues (math, etc) Short stature Early loss of ovarian function Very high miscarriage rate but if liveborn has a very good outlook/prognosis Generally not MR 4’8 average Lack of secondary sexual characteristics; infertility 18

19 Case #3 Ultrasound Pictures

20 Turner syndrome (45,X)

21 Prenatal Testing for Aneuploidy
In 2007, the American College of Obstetrics and Gynecology recommend that ALL women regardless of age should be counseled the risk of having a pregnancy with aneuploidy and given the option of both prenatal screening and prenatal diagnosis testing options

22 Modes of Prenatal Screening
Principles of Prenatal Screening: Uses various noninvasive tools (maternal serum, ultrasound) to provide a risk assessment for the most common trisomies It is not able to diagnose these conditions but determines if the patient is at either an increased or normal risk False positives and false negatives, cannot detect other conditions Types First trimester screen 11-14 weeks gestation Combines maternal age, ultrasound nuchal translucency measurements, evaluation of the nasal bone, and maternal serum levels of PAPP-A and free beta hCG Provides an adjusted risk for trisomy 21, 18, and 13 (x:xxx chance) Up to 91-95% detection for trisomy 21; 95% for trisomy 18 & 13 Does not screen for ONTDs; f/u with serum AFP only and/or u/s in 2nd tri Second trimester screen (multiple marker; AFP quad, AFP tetra) 15-20 weeks gestation Combines maternal age with serum levels of AFP, hCG, unconjugated estriol, and inhibin A Provides an adjusted risk for trisomy 21, 18, and open neural tube defects (x:xxx chance) 75-80% detection for trisomy 21; 60% for trisomy 18, and 80-85% for ONTDs Integrated or Sequential Screening Combines first & second trimester screening for ~90% detection of DS, 80% for T18

23 Modes of Prenatal Screening
Non-Invasive Prenatal Diagnosis Became available in the last year, still under study Maternal serum screening starting at 10 weeks which evaluating cell-free fetal DNA that circulates in maternal blood and determines the concentration of specifically tagged chromosomes On average, can detect: >99% (96-100%) detection of T21 (Down syndrome) 97%-99% (85-100%) of T18 cases 78.6%-91.7% ( %) of T13 cases Most labs with a <1% false positive rate Some labs are now including analysis for Turner syndrome & the presence of the Y chromosome False positives and negatives are still possible, still requires follow up prenatal dx with CVS or amnio Ultrasound at weeks Examines for markers/signs of chromosome aneuploidy; ONTDs, and other isolated birth defects Can be somewhat center-dependent ~50-60% detection for trisomy 21; >90% for trisomy 18, 13 and ONTDS Anatomy scan by OB; detailed/level II by perinate

24 Modes of Prenatal Diagnosis
Chorionic villus sampling (CVS) 10-12 weeks gestation Chromosome/genetic/DNA analysis performed on a sample of the chorionic villi 99.9% accuracy/detection of chromosome problems (genetic/DNA testing accuracy/detection is condition-specific) Risk of miscarriage 1/200 No analysis of AFP for ONTDs Performed transabdominally or transcervically Amniocentesis 15-20 weeks gestation Chromosome/genetic/DNA analysis performed on a sample on the fetal cells found in amniotic fluid Risk of miscarriage is as low as 1/1200 or 0.08% Provides 98-99% detection for ONTDs using analysis of amniotic fluid AFP

25 Tests ordered from CVS/Amnio
Karyotype Gold standard Karyotype is used to identify and evaluate the size, shape, and number of chromosomes in the fetus “Photograph” of the chromosomes Detects 99.9% of all major structural defects (trisomies, translocations, deletions)

26 Tests ordered from CVS/Amnio
FISH (Fluorescent in situ hybridization) Probes are made to “attach” to a specific region/section of a chromosome Many utilizations: Probes for common aneuploidy (allows for rapid detection) Probes for specific microdeletions/microduplicatons not able to be seen on karyotype

27 Tests ordered from CVS/Amnio
Chromosomal Microarray Evaluates specific areas (typically 100s of regions) along the human genome for gains or losses of chromosome segments at a much higher resolution than traditional karyotyping Typically done in cases of abnormal ultrasound findings and/or known family history of microarray abnormalities

28 Indications for a Genetic Counseling Referral
FINDING Family history genetic disease/birth defect/mental retardation AND/OR Consanguinity REASON TO CONSIDER CONSULTATION Review pedigree, assess degree of relatedness, discuss recurrence risks, methods of risk reductions, and discuss available testing options

29 The Family History in Genetics
Fundamental component of genetic consultation Visual record of the family Clarifying relationships between individual Allows for sorting of phenotypic features relevant to condition in question Assists in determining the mode of inheritance if evident Important in establishing rapport-can learn a lot of nongenetic information from pedigree Chief support people, social relationships, family “myths”

30 Putting it all together

31 Single Gene Inheritance Autosomal Dominant
Examples: Huntington Disease Achondroplasia Neurofibromatosis type 1 Marfan syndrome Some cases in the family will be “de novo” with no previous family hx Certain diseases are known to have high de novo rates and there is an increased risk with h paternal age



34 Single Gene Inheritance Autosomal Recessive
Cystic Fibrosis Sickle Cell Disease Thalassemia PKU Galactosemia Increased risk with consanguinity



37 Single Gene Inheritance X-Linked
Hemophilia A & B Duchenne MD Colorblindness Fragile X syndrome



40 Multifactorial Conditions
Examples: Heart defects Maternal diabetes, ace inhibitors, lithium Cleft lip/Cleft palate Cigarette smoking, folic acid deficiency, maternal medications Open neural tube defects Folic acid deficiency, MTHFR, maternal diabetes, anti-seizure medications


42 Indications for a Genetic Counseling Referral
FINDING Preconception/prenatal genetic carrier testing Environmental Hazards Maternal viral infection, teratogenic exposures Maternal conditions putting the fetus at risk Diabetes, PKU Infertility/Recurrent pregnancy loss Translocations; hereditary thrombophilias; patient has genetic/chromosomal condition REASON TO CONSIDER CONSULTATION Discuss inheritance & testing Discuss risks to pregnancy & testing Discuss various etiologies & offer workup as necessary

43 Carrier Screening Screening the population, or particular parts of the population for their risk to have a child with a recessive disorder Traditionally, carrier screening was performed/offered specific to the person’s ethnicity Since they are recessive conditions, a normal family history does not reduce the chances from general population risks 1/25 Europeans are carriers of CF 1/40 Europeans are carriers of SMA 1/12 Africans are carriers of Sickle cell and other hemoglobinopathies 1/9 Ashkenazi Jews are carriers of one of 9 “Jewish” conditions Now, with better and less expensive technology coupled with the fact that people are more often from multiple ethnic backgrounds, “Universal Genetic Carrier Screening” is utilized Screens for over 100 autosomal recessive genetic conditions 1/3-1/5 individuals are carriers of these conditions Same cost as in individual disease carrier test

44 Aim of Counseling Regarding Prenatal Diagnosis
Supply at risk families with information so they can make informed choices regarding pregnancy Provide a definitive answer for condition in question which allows for: An accurate diagnosis to provide a prognosis, management, and recurrence risks which allows for family to either continue or end a pregnancy Providing reassurance to at risk families when result is normal Allowing couples to prepare psychologically for the birth of an affected child Helping the health care professional plan delivery, management and care of an affected child Providing risk information to couples to assist in making decisions regarding their reproductive future: PGD, egg/sperm donors, adoption, natural pregnancy with diagnosis, no children Important points to question/inform patient Can condition be adequately screened for/diagnosed Will this information help them in any of the above ways such that it outweighs the risk of the procedure? No test can guarantee a “healthy baby”

45 Neonatal/Pediatric Genetics

46 Indications for Genetic Referral in Neonatal/Pediatric Setting
Developmental delay or mental retardation Dysmorphic features Under or overgrowth Failure to thrive Seizure disorder of unknown cause Hypotonia Abnormal or ambiguous newborn screening results Birth defect - either single or multiple Ambiguous genitalia Family history of genetic or chromosomal condition

47 Physical Examination Done by Medical Geneticist (MD)
Looking for dysmorphic features- subtle or distinct Anthropomorphic measurements Photos of other family members Some findings are familial---does not mean it is not a syndrome! Some findings are common---seen in 1-5% of the population (normal variant)

48 Dysmorphology Exam Head Shape/Hair pattern Ocular measurements Nose
Ears Philtrum/Mouth/Palate Maxillary region Mandible Chest/Back Limbs/Hands/Feet GU Skin

49 Common findings: seen in isolation
1-5% of population

50 Not so common anymore… 6-8 Café-au-lait macules, learning disability= Neurofibromatosis VSD, failure to thrive, distinct nose= VCFS

51 Importance Identifies etiology
Provides prognosis and appropriate medical management recommendations Provides accurate risk assessment for recurrence Isolated cleft palate or cleft lip Recurrence risk based on empiric data (3-5%) If syndromic, recurrence risk may be up to 50%. 22q11.2 deletion (DiGeorge syndrome), Van der Woude, Stickler syndrome

52 Other tools…. Karyotype FISH for specific suspected syndrome
Gene specific testing for suspected syndrome Chromosomal microarray Is now considered by many societies as a first-tier clinical diagnostic test for individuals with unexplained developmental delay/intellectual disability (DD/ID), autism spectrum disorders (ASD), or multiple congenital anomalies (MCA)

53 Newborn Screening – More Than “The PKU Test”!
CYSTIC FIBROSIS ENDOCRINE CONDITIONS: Congenital adrenal hyperplasia (CAH)*± • Congenital hypothyroidism* HEMOGLOBIN CONDITIONS:Sickle cell disease and other hemoglobinopathies* METABOLIC CONDITIONS: AMINO ACID CONDITIONS : Homocystinuria* • Hyperphenylalanemia, including • phenylketonuria (Pk ) Tyrosinemia* FATT y ACID OxIDATION CONDITIONS : Carnitine uptake defect • Carnitine palmitoyl transferase I deficiency (CPT I)* • Carnitine palmitoyl transferase II deficiency (CPT II) • Multiple acyl-CoA dehydrogenase deficiency • (MADD) Short chain acyl-CoA dehydrogenase deficiency • (SCAD) Medium chain acyl-CoA dehydrogenase deficiency • (MCAD)± Long chain 3 hydroxyacyl-CoA dehydrogenase • deficiency (LCHAD)*± Very long chain acyl-CoA dehydrogenase • deficiency (VLCAD)*± ORgANIC ACID CONDITIONS : Beta-ketothiolase deficiency • (BkD)± Glutaric acidemia, Type I (GA I)* • Isobutyryl CoA dehydrogenase deficiency • (IBD)± Isovaleric acidemia • (IVA)* ± Malonic aciduria • Maple syrup urine disease • (MSuD)± Methylmalonic acidemias (MMA/8 types)± • Propionic acidemia • (PA)*± 3-Hydroxy-3-methylglutaryl CoA lyase • deficiency (HMG)* 2-Methyl-3-hydroxybutyryl CoA dehydrogenase • deficiency (MBHD)* 2-Methylbutyryl CoA dehydrogenase • deficiency (2MBC)* 3-Methylcrotonyl CoA carboxylase deficiency (3MCC) • 3-Methylglutaconyl CoA hydratase deficiency (3MGH) • Multiple carboxylase deficiency UREA CyCLE CONDITIONS : Arginase deficiency • Argininosuccinate lyase deficiency (ASA)± • Citrullinemia± OTHER CONDITIONS : Biotinidase deficiency • Galactosemia±

54 Newborn Hearing Screening
1/1000 young children have a major hearing loss 50% of congenital hearing loss is genetic Early diagnosis is key to proper management

55 Pregnancy & Neonatal Loss

56 Chromosome Abnormalities in Pregnancy Loss
Approximately 25% of all clinically recognized pregnancies result in a loss <20 weeks = miscarriage Up to 50% are due to chromosome aneuploidy Most are due to nondisjunction with little increased risk of recurrence However, karyotyping can be indicated in repeat pregnancy loss since 2-5% of couples have a chromosomal abnormality causing the increased RR >20 weeks = stillbirth 5% are due to chromosome abnormalities However, some of these do increase the RR and when no other cause is known it is recommended to consider karyotype and/or microarray

57 Importance of a Genetic Workup
Can allow for a diagnosis which will answer some of the most important questions a parent will have Why? Will this happen again? Was it my fault? Therefore workups and often autopsies are essential

58 Grief and Bereavement Pregnancy loss is the same to the majority of parents, if not worse, than any other type of death It is extremely important to encourage, respect, and promote proper grieving of a loss no matter how early It’s often a loss of dreams/hopes/expectations Avoid comments that take away from the current situation: you can have another one, at least it was early, etc Important to: See, hold, spend time with the baby/body Take photos, they can always be kept in patient chart if not ready to take them home Name the baby, memorialize the baby in some meaningful way to the family Encourage the family to recognize their spiritual or religious beliefs Discuss cremation/burial options

59 Offering gentle and beautiful photography services in a compassionate and sensitive manner
Work done by professional photographers who volunteer their services and are trained in this specific area Photographers will work with families in order to fit their needs and desires Soft, gentle heirloom photographs of these beautiful babies are an important part of the healing process They allow families to honor and cherish their babies, and share the spirits of their lives

60 Perinatal Hospice “When the prenatal diagnosis of a lethal fetal anomaly has been established, some patients choose to continue their pregnancies. We propose a model of care that incorporates the strengths of prenatal diagnosis, perinatal grief management, and hospice care to address the needs of these families.” —Hoeldtke NJ, Calhoun BC. "Perinatal Hospice." Am J Obstet Gynecol Sept;185(3)525-9 Medical, emotional, and spiritual support through pregnancy, labor, birth, life and death Variety of services to help parents define a birth vision they are comfortable with Families may choose any of the services that fit their needs No typical family

61 “Regardless of the length of a baby's life or duration of illness, it is their lifetime. Both the infant and family deserve skilled and compassionate attention to their plight; a safety net throughout the experience; a palliative care approach, which emphasizes living fully those days, hours, and even moments.” —Sumner LH. Taking palliative care into pregnancy and perinatal loss. National Perinatal Association Bulletin. 2004;5(2). A news clip on Now I Lay Me Down To Sleep.

62 Thank You Questions?

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