Clinical Genetics Renata Gaillyová Clinical Genetics •Lecture hall - Clinic of pediatric infectious diseases, University Hospital Brno, Children's Hospital •Brno, Černopolní 22 • •Monday •7,30 – 8045 Clinical Genetics •9,00 - 12.30 Cytogenetics Clinical Genetics •Tuesday •7,30 – 11.00 Clinical Genetics •11,30-12.30 Visit on the Department of Medical Genetics, University Hospital brno, Children's Hospital. Černopolní 9, Building G, 3 floor •(Bring a medical mantle and shoes in the laboratory, please use the changing rooms for students •Wednesday •7,30-10.00 DNA diagnostics Clinical genetics •Dept. of medical genetics •Genetic prevention •Genetic diseases •Patients •Genetic counselling •Chromosome abnormalities •AD,AR,XR inheritance, disorders •Multifactorial inheritance •Teratogenes, Environmental hazards •Prenatal diagnosis •Reproductive genetics •Hereditary cancer Dept. of Medical genetics •Genetic ambulance •genetic counselling •Laboratory part •Cytogenetic laboratories •Prenatal cytogenetics •Postnatal cytogenetics •Oncocytogenetics •Molecular – cytogenetics •Lab. for DNA and RNA analysis (clinical genetics and oncogenetics) • • Characteristic of Medical Genetics •Preventive Medicine •Interdisciplinary cooperation •Information from genetics (disease, testing, posibilities) •Voluntary choice for patients •Informed agreement • Primary prevention of genetic •Before pregnancy •Folic acid (cca 1mg/day, 3+3 months) •Vaccination (rubella) •Genetic counselling •Contraception, adoption •Donor (oocytes, sperm) •Pregnancy planning •Environmental hazards (drugs, radiation, chemicals…) Secondary prevention of genetic •Prenatal diagnosis •Prenatal screening •Prenatal tests •Genetic counselling •Termination of pregnancy (the law in Czech Republic- end of 24. week of gestation) •Postnatal screening •Newborn screening • Genetics diseases •Chromosome abnormalities •about 0,6 -0,7% • •Monogen diseases •about 0,36% (in 1 000 000 newborns) • most then 90% in childhood • •Multifactorial (polygenic or complex) disorders •about 80% Patients on genetic departements •Dead person •Adults •Pregnant women •Fetuses •Children • • Patients on genetic departements •Positive family history (chromosome abnormality, congenital malformations, mental retardation, diseases…) •Pregnant women with encrease risk for the fetus •Infertility – sterility, repeated fetal loss •Donors (gamets) •Patients with tumours • Children •Congenital malformations Children •Suspition of mongenic hereditary diseases or inherited metabolic disorders and their families • Children •Suspition on congenital chromosom aberations (children with congenital malformations, abnormal face, atipical visage, pre- or postnatal growth retardation, premature birth) • Children •Precocious or delayed puberty •Malformations of the external or internal genitalia •Low or high figure Children •Before adoption Children or adults •Mental retardation •Psychomotor retardation •Developmental delay • Children and adults • •Gender identity disorder Children and adults • •people with long-term exposure to environmental pollutants •(alcohol, cigarettes, drugs, radiation) Children and adulds •patients with suspected hereditary cancer •patients with cancer (sporadic occurrence) Adults • •Gamete donors •(preventive tests) • Adults •Related partners •(increased risk for hereditary disease with AR inheritance) • • adults •Infertility •Repeated spontaneous abortions Pregnant women •With unfavorable family history Pregnant women •with adverse pregnancy history (chronic diseases with established therapies, acute disease in early pregnancy - temperature, drugs, X-rays, CT, vaccinations, toxoplasmosis, rubella, ...) • Pregnant women •Prenatal biochemical screening •(Pathology results) Pregnant women •Ultrasound prenatal screening – pathology results •Congenital malformations •Risk of chromosomal aberrations in the fetus Pregnant women •??? Age of parents ??? •relative indications Genetic counselling •Anamnesis •Family history •Pedigree analysis •Examining the patient •Laboratory analysis •Other examining - neurology, psychology, hematology, CT, MRI … • Mother •Name, surname, date of birth, maiden name •Place of birth •Place of birth of mothers parents •Relationship •Jobs - employment risks •Addictive substances • alcohol, cigarettes, • medication .. • Mother •Health problems from birth until today •Long-term medication •Long-term monitoring of a doctor •Gynecological anamnesis •The number of births, children, pregnancy, birth weight children, the health status of the children •The number of abortions, unsuccessful pregnancies •Unsuccessful attempt to pregnancy • Mother •In the case of health problems, if possible, to provide medical records from the attending physician •Long-term used drugs, how long • Father •Name, surname, date of birth •Place of birth •Place of birth ot hte fathers parents •Relationship •Jobs - employment risks •Addictive substances • alcohol, cigarettes, • drugs .. • • Father •Health problems from birth until today •Long-term medication •Long-term monitoring of a doctor •Number of children from any previous partners, their health status •The number of abortions, failed pregnancy (if any previous partner) •Unsuccessful attempt to become pregnant in previous partner • Father •In the case of health problems, if possible, to provide medical records from the attending physician •Long-term used drugs, how long • Child - Patient •Pregnancy •Swelling, nausea, protein in urine, sugar in urine, high blood pressure •Diseases in Pregnancy •Drugs in Pregnancy •Prenatal tests results Ultrasound, blood tests • Child •Birth - in time, early, after the deadline? •Complications, neonatal icterus, birth weight and length, nutrition •The mental and motor development •Diseases •Monitoring of specialists •Drugs •Test results • • Child •Clinical genetic examination •Weight, height •Atypical visage •Malformations •Psychological state •Behavior • • Pedigree- our patient III/3 Neonatal death Syndaktilie Epilepsy Congenital heart disease Cleft lip I II III 1 2 3 marriage divorce konsanguinity monozyg. twins dizygot. twins childless miscarriage man woman diseased Unknown gender carrier proband dead person Three-generation pedigree •Patient •Siblings •Children siblings •Parents •Parents siblings •Children of parents siblings •Parents parents Clinical examination The genome in individuals of the same type is the same Genotypes of individuals of the same species may be different GENOM X GENOTYP Next steps •Recommend the laboratory genetic testing •Recommend other specialists if needed •Require medical records •Make photodocumentation Genetic counselling •Specify exact diagnosis (if possible) • •Determine genetic prognosis •Is the disease hereditary? •Type of inheritance •Genetic risks for other family members •Posibilities of treatment, prenatal analysis Chromosome abnormalities chromosome1 VZOR2mit G-pruhy VZOR2karkon Congenital chromosome abnormalities •Autosomes •Gonosomes • •Numerous •Structural • •Balanced •Unbalanced • Populations frequency Chromosome abnormalities in spont. abortions Maternal age and chromosome abnormalities in AMC (per 1000) Risk of Down syndrom (live births) Happy nature Vision and hearing disorders Hypothyroidism Correlation between positive stimulation and height IQ Male sterility Alzheimer-like symptoms in 40 Výsky T 21 1 na 800. Je dobre známa závislosť výskytu trizómie 21 na veku matky , emiprické riziká stúpaju s vekom matky. U muža táto závisloslosť nebola popísaná. Down syndrome •47,XX,+21 or 47,XY,+21 •About 1/800-1000 newborns, 1/75 SA •Hypotonia, joint laxicity, soft skin, flat face, prominent intercanthal folds, slanted palpebral fissurs, specling of the irides (Brushfield´s spots), small, down set ears, small nose, protruding tongue, simian crease in the hands (about 45%), short statue, mental retardation, congenital heart disease (50%), A-V communis +21 Down syndrome (G-banding) Down syndrom- prenatal diagnosis •I. trimester screening •Ultrasound - 10.-12. week of. gest. •Nuchal translucency more than 2,5-3 mm, absence of nose bone •PAPP-A, free-beta hCG • •II. trimester screening •16. week – AFP, total hCG, uE3 • •20. week – US, congenital heart disease • II. Trimester screening •AFP • •hCG • •uE3 • •Risk 1 in 250 – borderline •Maternal age, week of gestation by US Edwards syndrome •47,XX(XY),+18 •1/5000-10 000 in newborns, 1/45 SA •gynekotropie 4:1 •SA - 95%, death before 1 year mostly • •hypotrophy, atypical hands and foots, profil, prominent nose, small chin, congenital defects • Edwards syndrome •1:5000 •IUGR, hyopotrophie •microcephalie •dolichocephalie •Cleft palate •Down set ears •micromandibula •Hands, feets •Other cong. malformations Prenatal dg. +18 – II. trimester •PAPP-A, FßhCG •AFP, HCG, uE3 • •Risk 1/250 - borderline •Ultrasonography Patau syndrome •47,XX(XY), +13 •1/5000-10 000 in newborns, 1/90 SA •95% SA •death before 1 year mostly • •cleft lip and palate bilateral, congenital defects (CNS, eyes, postaxial hexadaktily…) Patauův syndrom + 13 •Microcephalie •Trigonocephalie •skin defects in the hairy part calva •congenital defects of the brain (holoprosencephalie, arinencephalie) •micro-anophthalmia •Cleft lip, palate hexadactilie •heart defects • Turner syndrome •45,X ( in about 55% ), mosaicism, structural abnormalitites of X chromosome •1/2500 newborn girls, min. 95% SA •prenat.- hydrops foetus, hygroma coli • •postanatal lymphedema on foots, pterygium coli, congenital heart defect coarctation of aorta, small stature, other congenital defects, hypogenitalismus, hypergonadotropins, sterility-infertility Turner syndrom 45,X •1:2000 •hygroma colli •hydrops •Low weight in newborns •Lymfoedema •Pterygia •cubiti valgi •Aortal stenosis •Small statue •Sterility • Klinefelter syndrome •47,XXY •relatively frequent 1/600-1000 liveborn males •tall stature •hypogonadism, gynekomastia •sterility, infertility Others gonoseme abnormalities •47,XXX •47,XYY •48,XXXX •48,XXYY…. Structural chromosomam aberrations •deletion or a duplication of the genetic material of any chromosome, atypical structure - side by side to get the genetic material, which there normally is not - the effect of positional •partial-partial deletions •partial trisomy •inversions, insertions, duplications .... mutation2 Syndrom Wolf-Hirshorn 46,XX(XY),4p- •severe mental retardation •typical craniofacial dysmorphia - hypertelorism, pear nose, carp mouth, •pre-and postnatal growth retardation, •failure to thrive •other associated developmental defects - heart, urogenital tract ... Wolf-Hirschhorn syndrom (46,XX,4p-) Incidence? IUGR Hypotonia Charakteristic face Heart defects Hypotonie Hypotrophie Severe mental retardation Kardiovaskulárne anomálie okolo 40% -Atrioventrikulárny kanál Tracheoesofageálna fistula, pylorická stenóza , duodenálna atrézia 8% Hematologické-polycytemia, akútna lymfoblastická leukémia má zvýšený výskyt Syndrom Cri du chat 46,XX(XY),5p- •anomalies of the larynx causes the characteristic cry of a similar feline meow (only in infancy) •low birth weight and length •mental retardation, short stature, failure to thrive, small moon shaped face, the position antimongoloid eye slits, mikrocephalie •Other malformations and birth defects Cri du chat 46,XX(XY),5p- •1:50 000 •Typicaly cri in newborns •laryngomalacie •antimongoloid •epicanthi •hypotonie •hypotrofie Mikrocytogenetic Molekular cytogenetic •FISH (fluorescenc in situ hybridisation), M-FISH, SKY (spektral karyoptyping), CGH (komparativ genom hynridization), MLPA •mikrodeletions or mikroduplications, marker chromosoms, complex rearegemnts, oncology – oncocytogenetics,fast prenatal diagnostics …) •fast methods (possible forprenatal dg) •metafase and intesfase examination FISH Komparativ genom hybridisation 8dobr1 pokus88d MLPA Multiplex Ligation-Dependent Probe Amplification mrc_holland_font40 the_mlpa_reaction1 2 3 4 5 6 7 8 9 10 11 12 Microdeletions •Di George syndrome (del 22q11) • •Prader-Willi / Angelman syndrome (del15q11-13) • •Williams Beuren syndrome (del7q11.23) • Syndrom Di George •Velo - Kardio- Facial syndrome •CATCH 22 •Congenital heart desease - conotruncal, craniofacial dysmorfism, thymus aplasie, imunodefitient¨cy, hypoparathyreoidismus Williams - Beuren syndrom •del 7q11.23 • •Facial dysmorfie - Elfin face, congenital heart disease, aortal or pulmonal stenosis, hypokalcemie, small statue, MR, hernie,... Prader-Willi syndrom •Hypotonie, hypotrofie in small children • •PMR, small statue, obesity, hyperfagie, akromikrie, hypogonadismus • •mikrodeletion15q11-12 paternal • Angelman syndrom •Severe mental retardation •Epilepsie •Laughter •severely delayed speech development •mikrodeletion 15q11-12 mat The telomere Rearangement in about 6-8% children with mental retardation with or without congenital defect (FISH, HR-CGH, MLPA) Mendelian inheritance Monogenetic diseases Autosomal Dominant •The sexes are involved equaly •Heterozygotes are mostly affected clinically •risk 50% for sibs and children •new mutations •penetrance, expresivity Pedigree AD inheritance • the risk 50% healthy ill AD - diseases •Neurofibromatosis 1 and 2 •Achondoplasia •Huntington disease •Marfan syndrome •Myotonic dystrophy • • Autosomal Recesive •Heterozygotes are generally unaffected clinicaly •The sexes are involved equaly •An individual manifesting a recesive disorder usually has heterozygous parents •Once a homozygote is identified, the recurence risk for other child of some parents is 25% • Pedegree - AR inheritance •The risk for next child 25% carrier carrier healthy ill carrier healthy AR - diseases •Cystic fibrosis •(frequency of heterozygotes CR- 1/26) • •Phenylketounria (1/40) • •Congenital adrenal hyperplasia (1/40) • •Spinal muscular atrophy (1/60-80) • Cystic fibrosis •Localized on chromosome 7q • •Frequency of Cystic Fibrosis in the Czech Republic: about 1/2000 – 1/3000 • •Frequency of heterozygots in the Czech Republic about 1/25-1/29 • •About 1600 mutations in CFTR gene were identified • Cystic fibrosis •disease affecting multiple organs Respiratory tract liver pankreas intestine reproductiv failure sweat gland The reason for CFTR gene analysis •Suspition on Cystic fibrosis in a patient •Cystic fibrosis in the family •Partners of hyterozygots for Cystic fibrosis •Repeated fetal loss •Sterility •Relationship of the partners •Others • CFTR gene - distrubitions od mutations Most frequent CFTR mutations in Czech population Mutation Frequency in CR (%) F508del 70,7 CFTRdele2,3(21kb) 6,4 G551D 3,7 N1303K 2,8 G542X 2,1 1898+1 GtoA 2,0 2143delT 1,1 R347P 0,74 W1282X 0,6 X-linked Recesive •Females are not affected as severaly as males or are not affected •An affected male cannot transmit the train to his sons, becose the trait is on X-chromosome, and the father must necessarily transmit his Y-chromosome to a son •All of the daughters of an affected male must be carriers, because the only X-chromosome that the father can give to a daughter contains the mutation • • X-linked Recesive •Risk for daughters of a carrier - mother •50% for carrier • •Risk for sons of carrier - mother •50% for diseas X- recesive inheritance X XY XX X XY XR - diseases •Hemophilia A and B • •Duchenne and Becker muscular dystrophy • •Fragile X chromosome - X-linked disease Multifaktorial –polygenic inheritance Dieseases with complex heritability Teratogens Charakterization •disease with multifactorial inheritance include not mendelian types of inheritance •diseases exhibit familial aggregation, because the relatives of affected individuals more likely than unrelated people to carry diseases predisposing predisposition Charakterization •in the pathogenesis of the disease play a basic role non-genetic factors •disease is more common among close relatives and in distant relatives is becoming less frequent Examples •Congenitzal heart defects (VCC) 4-8/1000 •Cleft lip and palate (CL/P) 1/1000 •Neural tube defects (NTD, anencefalie, spina bifida,..) 0,2-1/1000 •Pylorostenosis •Congenital hip dislocation •Diabetes mellitus – most types •Ischemic heart desoease •Esential epilepsy Common congenital defects Congenital heart diseases •0,5 - 1% in liveborn infantsn - population incidence •etiology not known mostly •about 3% + chromosomal syndromes (+21,+13,+18, 45,X, 18q-, 4p-, del 22q11 Di George sy) •some mendelian syndromes associated with congenital heart disease (Holt-Oram, Williams, Noonan, Ivemark... Congenital heart diseases prenatal diagnosis •For most serious congenital heart diseases •Ultrasonography in 21. week of gestation - by specialists for prenatal kardiology Congenital heart disease - genetic risks Congenital heart disease genetic risks Cleft lip and palate •Population incidence CL 1/500-1/1000 •Multifactorial mostly •With chromosomal trisomies (+13,+18) •Syndromes associated with CL/CP/CLP •(van der Woude sy, EEC sy, Pierre Robin sequence…) •Prenatal diagnosis by ultrasonography not sure Cleft lip and palate- genetic risks Neural tube defects •Multifactorial inheritance (risk for I. degree relatives about 2 - 4%) •Maternal serum AFP screening •Prenatal diagnosis by ultrasonography •Raised AFP levels in amniotic fluid •Primary prevention in pregnancies by folic acid •Risk populations - probably related to nutritional status Teratogeny •teratogen is a substance whose effect on embryo or fetus may cause abnormal development action may be direct or through the maternal organism Human Teratogens •Physical (radiation, heat (fever), mechanical impact) •Chemical (chemicals, drugs) • •Biological (infection, fungus ...) •Metabolic imbalance (disease mother) • The effect of teratogens depends on : •dose • •length of the action •contact time •genetic equipment of the fetus and the mother Critical period •14.-18. days after conception – the rule „all od nothing “ • •18.-90. day – organogenesis •The most sensitive period for the emergence of developmental defects Drugs •Distribution of medicines practice into categories • A • B • C • D • X •Food and Drug Administarion, 1980 A •in controlled studies have shown no evidence of risk to the fetus in the first trimester of fetal development or influence in the next period of pregnancy product appears to be safe B •Animal reproduction studies demonstrate a risk to the fetus, but there's no controlled studies in women Animal reproduction studies have shown adverse effects, but in controlled studies in women have not been confirmed C •Animal studies confirm the teratogenic embryotoxic or other adverse effects on the fetus, •non-controlled studies in women •lack of studies in animals and humans product should be administered with caution and only in cases where the benefit for the woman of his administration exceeds the potential risk to the fetus D •risk to the human fetus is known •medicine may be administered in a situation where its use for a woman needed (lifesaving) •no other safer drug is available • X •studies in animals and in humans clearly demonstrate a teratogenic effect •drugs absolutely contraindicated in pregnancy • Drugs with teratogenic effect •Thalidomid •Hydantoin •Valproic acid •Anti coagulans - Warfarin •Trimetadion •Aminopterin •Methotrexat •Cyklophosphamid • • • Drugs with teratogenic effect •Retinoids •Lithium •Thyxreostatic drugs •Androgens •Penicilamin •Enelapril, Captopril •Antituberkulotics-Streptomycin Thalaidomid •congenital heart defects •limb reduction anomalies •Other congenital defects (gastrointestinal, urogenital tract orofacial – ears anomalies, CNS defects..) Hydantoin •Atypicaly face, growth retardation, mild mental retardation, behavioral problems, hypoplastic nails and fingers • Aminopterin a Methotrexat •folic acid antagonist facial dysmorfism, cleft lip and/or palate, small mandible, malá dolní čelist, ears anomalies, hydrocephalus, growth and mental retardation, miscarriage • Warfarin •coumarin antikoagulans •facial dysmorfism – nasal cartilage hypoplasia, CNS - defects • Retinoids •Cleft lip and palate, mikrognatia, eyes anomalies, ears dysplasia •Defects of CNS •Thymus hypoplasia •Limb defects Infection •Toxoplasmosis •Rubella •Cytomegalovirus •Herpesvirus •Others (parvovirus, antropozoonosy, chlamydia..) • • TORCH Toxoplasmosis •chorioretinitis •hydrocephalus or microcephaly •intracranial calcification, mental retardation •icterus, hepatosplenomegalia, carditis •prematurity • •positiv IgM in the mother – treatment with Rovamycin •Prenatal dg.: serology, DNA-PCR) Rubella •hearing and vision impairment (cataract, glaucoma, mikroftalmia, blidness) •mental retardation •Cong. heart defects •icterus, hepatosplenomegalia • •prevention- vaccination Cytomegalovirus •Intrauterin growth retardation •mikrocephaly, cacification in the brain, mental retardation, •hepatosplenomegaly • •Repeated maternal infection is possible •Prenatal dg.: serology,DNA-PCR Varicella zoster •Skin lesions and defects •Brain domage, mental retardation •Eye defects • •Prenatal dg. - serology, DNA-PCR Metabolic dysbalance •Fetal alcohol syndrom (FAS) •Maternal Phenylketonuria •Maternal Diabetes mellitus •Maternal Hypothyreosis Fetal alcohol syndrom •Hypotrophy, growth retardation, mental retardation •facial dysmorphism •Congenital heart defects •Limb defekts • •Abuse of 60g pure alcohol / day (longterm) •Combine with malnutrition, folic acid deficit... Maternal Phenylketonuria •Low birth weith •nízká porodní váha, hypertonus •mikrocefalie, PMR •VCC •hyperaktivita • •novorozenecký screening •(frekvence 1/10 000 novorozenců, dědičnost AR) •Léčbu je třeba zahájit do 3 týdnů, jinak PMR Prenatal diagnosis •Non invasive - screening • •Invasive - CVS, AMC, kordocentesis Prenatal screening (CR) •Ultrasound (12. - 2 0. - 33. week) •Ultrasound 20.week – cong. defect •Ultrasound 20-22. week – cong. heart defect • •Free beta hCG, PAPP-A, US-NT:10-14. week of gestation •AFP, hCG, uE3 - 16.-18.week of gestation • Indications for prenatal diagnosis / counselling •Advanced maternal age (35) •Risk factors – US – congenital defects •Family history of known conditions for which diagnosis is possible (DNA analysis) •Known chromosomal abnormality (de novo finding in previous child, structural change in parents) •Positive prenatal screening for chromosomal abnormalities • Amniocentesis OBRA3 Preimplantation Genetic Diagnostics X PG Screening •PGD high genetic risk • • • •PGS frequent aneuploidies Genetic counselling in infertility Infertility •Is the infertility one aspect of a genetic disorder that might be transmitted? •Will correction if infertility give an increased risk of malformations in the offspring? • •Genetic testing before use of metods of asisted reproduction. Infertility •Patological examination of the abortus where possible, this may identify major structural malformations. •Cytogenetic study of parents, this is especialy important where a structural abnormality is present. •In general the finding of a chromosome abnormality in the abortus but not in parent is not likely to be relevant or affect the genetic risks. Infertility •A search for possible lethal mendelian causes (consanguinity- risk for AR diseases, X-linked dominant disorders lethal in male, myotonic dystrophy which gives heavy fetal loss in the offspring of mildly affected women) •Inherited trombophilias in women with recurrent abortions ( factor V Leiden, factor II - G20210A, hyperhomocystinaemia ? (MTHFR - C677T) Sterility in male •AZF deletions (DAZ gene) Yq • •CFTR mutations and polymorphisms Genetic risk in cancer Genetic testing in oncologic patients •Diagnosis •Therapy •Prognosis •Minimal residual disease Genetic risks in cancer •Tumours following mendelian inheritance (most AD, about 5%) •Genetic syndromes predisposing to malignancy •Embryonal and childhood tumours •Common malignant tumours of later life Hereditary cancer syndromes •AD inheritance • •Preventive, pre-symptomatic testing • •Assotiated problems • •Prevention Hereditary cancer syndromes following AD inheritance •Brest cancer – BRCA 1 and BRCA 2 •Familial Adenomatous Polyposis coli - FAP •Von Hippel – Lindau syndrome- VHL •Retinoblastoma •Neurofibromatosis- NF1, NF2 •Li-Fraumeni syndrome •Lynch syndrome – hereditary non polypous colon cancer - HNPCC Genetic testing in Hereditary cancer syndromes •Tests are voluntary •Mostly in adults only • •In children only when prevention in childhood is present and when the risk of tumours is in childhood • •