TRIDOMY 18 Essay, Research Paper
TRISOMY 18 SYNDROME
DEFINITION:
A chromosomal disorder resulting in a syndrome characterized by specific (small) dysmorphic features and organ malformations.
EPIDEMIOLOGY:
incidence: 1/8000 live births
most die in embryonic or fetal life
2nd most common autosomal aberration
2nd most common multiple malformation syndrome
age of onset:
newborn
risk factors:
advanced maternal age
F > M (4:1)
HISTORY:
1960
first recognized as a specific clinical entity by the discovery of an extra chromosome 18 in babies with a particular pattern of malformation by three independent groups (Edwards et al., Patau et al., Smith et al.)
PATHOGENESIS:
1. Genetics
1. Trisomy 18
90% of cases
due to meiotic nondisjunction
less than 1% recurrence rate
2. Mosaicism
10% of cases
due to postzygotic (postfertilization) mitotic nondisjunction
leads to the partial clinical expression of Trisomy 18 with a longer survival
3. Translocations
very rare
give rise to partial trisomy 18 syndromes
short arm:
causes non-specific clinical features with mild or no mental deficiency
long arm:
entire:
clinically indistinguishable from trisomy 18
distal 1/3 -> ?:
partial clinical picture of trisomy 18 with a longer survival and less profound mental retardation
CLINICAL FEATURES:
1. Dysmorphic Features
1. Facial
microcephaly with prominent occiput
narrow bifrontal diameter
short palpabral fissures
low-set malformed ears
cleft lip +/- palate
narrow palatal arch
micrognathia
2. Skeletal
neck
webbed
chest
short sternum
widely spaced nipples
hips:
small pelvis, congenital dislocation of the hips, limited hip abduction
extremities:
phocomelia
rockerbottom feet or equinovarus
short dorsiflexed big toes
fixed flexion deformity of the fingers (overlapping of the 2nd and 5th fingers over the 3rd and 4th fingers)
simple arch pattern of the fingers and toes
hypoplasia of fingernails
single crease of 5th finger or all fingers (absence of interphalangeal flexion creases)
simian crease
2. Organ Malformations
1. Central Nervous System
severe mental retardation
hypotonia -> hypertonia
neural tube defects
poor suck and weak cry
failure to thrive
ocular anomalies
2. Respiratory
apnea
3. Cardiovascular( >95%)
major: VSD, ASD, PDA
minor: transposition, ToF, coarctation, anomalous coronary artery, dextrocardia, aberrant subclavian artery, arteriosclerosis, PS, bicuspid aortic and/or pulmonic valves
4. Gastrointestinal
inguinal, umbilical, and/or diaphragmatic hernia
congenital defects:
diastasis recti, heterotopic pancreas, malrotation, Meckel’s, tracheoesophageal fistula
5. Genitourinary
cryptorchidism
congenital defects:
double ureter, ectopic kidney, horseshoe kidney, hydronephrosis, polycystic kidney
INVESTIGATIONS:
1. Imaging Studies
to rule out organ malformations:
cardiovascular anomalies – Echo
gastrointestinal anomalies – Barium Swallow, Endoscope
genitourinary anomalies – Ultrasound
2. Karyotyping
MANAGEMENT:
1. Supportive
very poor prognosis with:
30% dying by 1 month of age
50% dying by 2 months of age
90% dying by 12 months of age
genetic counselling
recurrence rate depends on genotype
Другие работы по теме:
Poem Fading Away Essay Research Paper as
Poem: Fading Away Essay, Research Paper as i gaze at the falling rain trying to get away from all the pain som uch tension rising in the air dying inside does anyone care
Romeo An Juliet Essay Research Paper hi
Romeo An Juliet Essay, Research Paper hi i need an essay about a character in romeo and juliet that demonsrtated maturity. in a well developed multi pagraph essay and say why you think the character’s maturity was greater than the other characters in the play.
Oh Really Essay Research Paper Oh Reallyyou
Oh Really? Essay, Research Paper Oh Really, you think i am a lark, the dogs they run and bark, but when i say to them, shut up shut up shut up, you say to be nice to them,
Shane Essay Research Paper Sometimes I need
Shane Essay, Research Paper Sometimes, I need you more than I need air And sometimes I miss you more than I will forever, never forget the times that we have shaared. The are priceless
Poem Belong Essay Research Paper Where I
Poem: Belong Essay, Research Paper Where I belong I am weak, I am strong I will fit where I belong don’t know where it is for now but it will come, if I allow tomorrow, I start a brand new day
Down Syndrome Essay Research Paper Down Syndrome
Down Syndrome Essay, Research Paper Down Syndrome or Trisomy 21 as it is also commonly known, is a genetic condition that for many years has been shrouded in fear, darkness & shame. There is absoultely nothing to fear, and there never should be any feelings of shame, it is not the persons fault. The only darkness associated with down syndrome is the ignorance many people have towards it.
Trisomy 13 Essay Research Paper Trisomy 13
Trisomy 13 Essay, Research Paper Trisomy 13 (Patau Syndrome) Dr. C.J Gamble To the Parents or Legal Guardians of Patient XC902-V42 In our extensive testing it was revealed to us that your son suffers from a genetic disorder called Trisomy 13 or Patau’s Syndrome. Trisomy 13 is a syndrome caused by an extra 13th chromosome.
Meiosis Essay Research Paper State that meiosis
Meiosis Essay, Research Paper State that meiosis is a reduction division in terms of diploid and haploid numbers of chromosomes Outline the process of meiosis including pairing of chromosomes followed by
Him Essay Research Paper I think about
Him Essay, Research Paper I think about him day and night The though won’t go away And, oh, how I would hold him tight every second of the day He is perfect, that is true, not an average me or you
Poem She Sat Essay Research Paper She
Poem: She Sat Essay, Research Paper She sat… helpless in her room praying to whatever god there may be to let her call to him. could god ignore such a painful cry?
Chromosome Probes Essay Research Paper Chromosome ProbesSensitive
Chromosome Probes Essay, Research Paper Chromosome Probes Sensitive chromosome probes recently discovered by a University of Toronto geneticist will make it easier to detect certain types of genetic and prenatal diseases, as well as being used to determine paternity and provide forensic evidence in criminal
School Essay Research Paper School Where
School Essay, Research Paper School! Where did they come up with that name? I guess because it rhymes with lame Now this rhyme you read will be quite corny Please don’t get upset, mad, or horny
Ode To Boys Essay Research Paper We
Ode To Boys Essay, Research Paper We like them But do they like us The ones we do never fuss They don’t stop in And we wonder why We stress, we bitch We sometimes cry
Crying Again Essay Research Paper The Sky
Crying Again Essay, Research Paper The Sky is crying again And i am crying again. When did it start? When will it end? How’d i wind up with out a friend? Tears from my heart cling to my soul.
ChromoA Essay Research Paper Chromosome Probes at
Chromo(A) Essay, Research Paper Chromosome Probes at the University of Toronto Sensitive chromosome probes recently discovered by aUniversity of Toronto geneticist will make it easierto detect certain types of genetic and prenataldiseases, as well as being used to determine paternityand provide forensic evidence in criminal cases.
Life Is Like Essay Research Paper Life
Life Is Like Essay, Research Paper Life is like a car. When it?s new, it usually works all right. As time drives by, it breaks down and needs repairs. Life is like a leaf. In its youth, it
Hell Day Essay Research Paper Hell day
Hell Day Essay, Research Paper Hell day is a fun day where everything is like a burn day. If you would listen you could learn about this day and be apart of this day. If you are wise then you will relize that hell day is satans Birthday!!!!!!!!!!!!!!
Dare Essay Essay Research Paper What DARE
Dare Essay Essay, Research Paper What D.A.R.E Means To Me Dare has prepared me to say no to drugs in eight different ways. If anyone asks me to do drugs I will know what to do, such as- just ignoring the person or just
The Playground Essay Research Paper I have
The Playground Essay, Research Paper I have a friend I used to know who had a playground where we would go The times we had are fresh in my mind but they are from another time
Down Syndrome Report Essay Research Paper Down
Down Syndrome Report Essay, Research Paper Down Syndrome Report by: SCHOOL SUX The chromosomal abnormality involved in most cases of Down syndrome is trisomy-21, or the presence of three copies of the 21st chromosome. As a result,
How To Writing A Research Essay Essay
, Research Paper How To Writing A Research Essay The toughest part of the essay, for me, was taking all the information I had gained and reduce it to a mere few pages essay. After all, quality is better