Turner syndrome overview: Difference between revisions

Jump to navigation Jump to search
No edit summary
No edit summary
Line 6: Line 6:


==Historical Perspective==
==Historical Perspective==
Turner syndrome was first described in 1938 by Henry Turner when he noticed a triad of short stature, cubitus valgus and pterygium colli. Other scientists went to to discover the pathophysiology of the 45 XO karyotype and the presence of streaked ovaries.


==Classification==
==Classification==
There is no established system for the classification of Turner syndrome.


==Pathophysiology==
==Pathophysiology==
Humans have 46 [[chromosomes]]. Chromosomes contain all of your [[genes]] and [[DNA]], the building blocks of the body. Two of these chromosomes, the [[sex chromosomes]], determine if you become a [[boy]] or a [[girl]]. Loss the paternally or maternallyt derived X chromosome would lead to the class 45 XO karyotype. Sometimes, an individual may have two cells lines with different genetic makeups. The percentage of this mosaicism is said to determine the severity of the phenotype in the patient. Structural abnormalities such as the formation of a ring chromosome or an isochromosome and other mechanisms such as lyonization or imprinting also play a role in the pathophysiology of Turner Syndrome.


==Causes==
==Causes==
Humans have 46 [[chromosomes]]. Chromosomes contain all of your [[genes]] and [[DNA]], the building blocks of the body. Two of these chromosomes, the [[sex chromosomes]], determine if you become a [[boy]] or a [[girl]]. Females normally  have two of the same sex chromosomes, written as XX. Males have an X and  a [[Y chromosome]] (written as XY).
In [[Turner syndrome]], cells are missing all or part of an [[X chromosome]]. The condition only occurs in females. Most commonly, the female patient has only one X chromosome. Others may have two X chromosomes, but one  of them is incomplete. Sometimes, a female has some cells with two X  chromosomes, but other cells have only one.


==Differentiating Turner syndrome from Other Diseases==
==Differentiating Turner syndrome from Other Diseases==
[[Turner's syndrome]] must be differentiated from other [[diseases]] that cause latency in [[secondary sexual characteristics]] development, such as [[constitutional delay of puberty]], [[hypopituitarism]], [[delayed puberty]], and [[chromosomal abnormalities]]. [[Chromosomal abnormalities|Chromosomal abnormality]] is [[Noonan's syndrome]].


==Epidemiology and Demographics==
==Epidemiology and Demographics==
The incidence rate of Turner is 1 of 2500 live births. Turner Syndrome patients have a higher mortality rate compared to the general population.


==Risk Factors==
==Risk Factors==
There is currently no known cause for Turner syndrome, though there are several theories surrounding the subject.


==Screening==
==Screening==
Screening for complications of Turner syndrome starts as early as a prenatal visit. Abnormal maternal serum screening tests or an ultrasound detecting structural anomalies such shortned limbs, cystic hygromas, congenital heart defects or increased swelling of the hands or feet may point towards a diagnosis of Turner syndrome. As the years progress, screening involves a multidisciplinary combination of lab investigations (such as serum gonadotrophins,liver function tests, renal function tests, etc), referral to other departments (cardiology, endocrinology, ophthalmology, etc) and tools such as DEXA scans, X-rays, echocardiography, etc.


==Natural History, Complications, and Prognosis==
==Natural History, Complications, and Prognosis==


Natural history of the patient would depend on the age of the diagnoses and what complications have developed by the time the patients presents to the physician. Congenital lymphedema may take several years to decrease. The patient experiences low self esteem due to their short stature, decreased visual spatial functioning, hyperactivity, poor facial recognition and preference for social isolation. As soon as the patient is capable of understanding, counseling regaridng the risks and benefits of Turner syndrome should be explained. When compared to the general population, Turner syndrome patients have an increased mortality rate.


==Diagnosis==
==Diagnosis==
===Diagnostic Study of Choice===
===Diagnostic Study of Choice===
The diagnostic study of choice for the diagnosis of Turner syndrome is karyotype analysis of 30 blood lymphocytes. Examination of additional cells , polymerase chain reaction, fluorescent in situ hybridization, Southern blotting, restricted fragment length polymorphisms and new generation gene sequencing techniques may be employed following the interpretation of the initial karyotype.


===History and Symptoms===
===History and Symptoms===
Natural history of the patient would depend on the age of the diagnoses and what complications have developed by the time the patients presents to the physician. Congenital lymphedema may take several years to decrease. The patient experiences low self esteem due to their short stature, decreased visual spatial functioning, hyperactivity, poor facial recognition and preference for social isolation. As soon as the patient is capable of understanding, counseling regaridng the risks and benefits of Turner syndrome should be explained.


===Physical Examination===
===Physical Examination===
Physical examination may be suggestive of thyroid dysfunction, congenital heart defects, inflammatory bowel disease, characteristic skeletal deformities and body habitus/skin manifestations.


===Laboratory Findings===
===Laboratory Findings===
Laboratory investigations serve as important screening tools for thyroid dysfunction, renal dysfunction, liver dysfunction, new onset diabetes mellitus,vitamin D deficiency and ovarian reserve.


===Electrocardiogram===
===Electrocardiogram===
An electrocardiogram is not employed in the diagnosis of Turner syndrome.


===X-ray===
===X-ray===
A x-ray may be used to diagnose cardiac and skeletal abnormalities.


===Echocardiography and Ultrasound===
===Echocardiography and Ultrasound===
Prenatal ultrasounds my show a left-sided cardiac defect, renal anomalies, growth retardation, relatively short limbs, fetal edema, cystic hygroma, polyhydramnios and brachycephaly. Echocardiographies and renal ultrasounds help detect structural defects.


===CT scan===
===CT scan===
Simple CTs or CT angiographies are helpful in screening/detecting the following cardiac abnormalities.


===MRI===
===MRI===
Cardiac MRIs are helpful in screening/detecting the following cardiac abnormalities and functional MRIs have been used to study neural pathways responsible for poor visual spatial skills and executive function.


===Other Imaging Findings===
===Other Imaging Findings===
There are no other imaging findings associated with Turner syndrome.


===Other Diagnostic Studies===
===Other Diagnostic Studies===
The diagnostic study of choice for the diagnosis of Turner syndrome is karyotype analysis of 30 blood lymphocytes. Findings may include the classic 45 XO karyotype, mosaicism and structural anomalies like isochromosomes or ring chromosomes.


==Treatment==
==Treatment==
===Medical Therapy===
===Medical Therapy===


Line 57: Line 99:


===Secondary Prevention===
===Secondary Prevention===
There are no established measures for the secondary prevention of Turner Syndrome. Secondary prevention is aimed at preventing complications of Turner syndrome. This involves frequent screening of complications.


==References==
==References==

Revision as of 10:40, 18 August 2020

Turner syndrome Microchapters

Home

Patient Information

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Turner syndrome from other Diseases

Epidemiology and Demographics

Risk Factors

Screening

Natural History, Complications and Prognosis

Diagnosis

Diagnostic Study of Choice

History and Symptoms

Physical Examination

Laboratory Findings

Electrocardiogram

X Ray

Echocardiography and Ultrasound

CT

MRI

Other Imaging Findings

Other Diagnostic Studies

Treatment

Medical Therapy

Interventions

Surgery

Primary Prevention

Secondary Prevention

Cost-Effectiveness of Therapy

Future or Investigational Therapies

Case Studies

Case #1

Turner syndrome overview On the Web

Most recent articles

Most cited articles

Review articles

CME Programs

Powerpoint slides

Images

American Roentgen Ray Society Images of Turner syndrome overview

All Images
X-rays
Echo & Ultrasound
CT Images
MRI

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

FDA on Turner syndrome overview

CDC on Turner syndrome overview

Turner syndrome overview in the news

Blogs on Turner syndrome overview

Directions to Hospitals Treating Turner syndrome

Risk calculators and risk factors for Turner syndrome overview

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Akash Daswaney, M.B.B.S[2]

Overview

Historical Perspective

Turner syndrome was first described in 1938 by Henry Turner when he noticed a triad of short stature, cubitus valgus and pterygium colli. Other scientists went to to discover the pathophysiology of the 45 XO karyotype and the presence of streaked ovaries.

Classification

There is no established system for the classification of Turner syndrome.

Pathophysiology

Humans have 46 chromosomes. Chromosomes contain all of your genes and DNA, the building blocks of the body. Two of these chromosomes, the sex chromosomes, determine if you become a boy or a girl. Loss the paternally or maternallyt derived X chromosome would lead to the class 45 XO karyotype. Sometimes, an individual may have two cells lines with different genetic makeups. The percentage of this mosaicism is said to determine the severity of the phenotype in the patient. Structural abnormalities such as the formation of a ring chromosome or an isochromosome and other mechanisms such as lyonization or imprinting also play a role in the pathophysiology of Turner Syndrome.

Causes

Humans have 46 chromosomes. Chromosomes contain all of your genes and DNA, the building blocks of the body. Two of these chromosomes, the sex chromosomes, determine if you become a boy or a girl. Females normally have two of the same sex chromosomes, written as XX. Males have an X and a Y chromosome (written as XY). In Turner syndrome, cells are missing all or part of an X chromosome. The condition only occurs in females. Most commonly, the female patient has only one X chromosome. Others may have two X chromosomes, but one of them is incomplete. Sometimes, a female has some cells with two X chromosomes, but other cells have only one.

Differentiating Turner syndrome from Other Diseases

Turner's syndrome must be differentiated from other diseases that cause latency in secondary sexual characteristics development, such as constitutional delay of puberty, hypopituitarism, delayed puberty, and chromosomal abnormalities. Chromosomal abnormality is Noonan's syndrome.

Epidemiology and Demographics

The incidence rate of Turner is 1 of 2500 live births. Turner Syndrome patients have a higher mortality rate compared to the general population.

Risk Factors

There is currently no known cause for Turner syndrome, though there are several theories surrounding the subject.

Screening

Screening for complications of Turner syndrome starts as early as a prenatal visit. Abnormal maternal serum screening tests or an ultrasound detecting structural anomalies such shortned limbs, cystic hygromas, congenital heart defects or increased swelling of the hands or feet may point towards a diagnosis of Turner syndrome. As the years progress, screening involves a multidisciplinary combination of lab investigations (such as serum gonadotrophins,liver function tests, renal function tests, etc), referral to other departments (cardiology, endocrinology, ophthalmology, etc) and tools such as DEXA scans, X-rays, echocardiography, etc.

Natural History, Complications, and Prognosis

Natural history of the patient would depend on the age of the diagnoses and what complications have developed by the time the patients presents to the physician. Congenital lymphedema may take several years to decrease. The patient experiences low self esteem due to their short stature, decreased visual spatial functioning, hyperactivity, poor facial recognition and preference for social isolation. As soon as the patient is capable of understanding, counseling regaridng the risks and benefits of Turner syndrome should be explained. When compared to the general population, Turner syndrome patients have an increased mortality rate.

Diagnosis

Diagnostic Study of Choice

The diagnostic study of choice for the diagnosis of Turner syndrome is karyotype analysis of 30 blood lymphocytes. Examination of additional cells , polymerase chain reaction, fluorescent in situ hybridization, Southern blotting, restricted fragment length polymorphisms and new generation gene sequencing techniques may be employed following the interpretation of the initial karyotype.

History and Symptoms

Natural history of the patient would depend on the age of the diagnoses and what complications have developed by the time the patients presents to the physician. Congenital lymphedema may take several years to decrease. The patient experiences low self esteem due to their short stature, decreased visual spatial functioning, hyperactivity, poor facial recognition and preference for social isolation. As soon as the patient is capable of understanding, counseling regaridng the risks and benefits of Turner syndrome should be explained.

Physical Examination

Physical examination may be suggestive of thyroid dysfunction, congenital heart defects, inflammatory bowel disease, characteristic skeletal deformities and body habitus/skin manifestations.

Laboratory Findings

Laboratory investigations serve as important screening tools for thyroid dysfunction, renal dysfunction, liver dysfunction, new onset diabetes mellitus,vitamin D deficiency and ovarian reserve.

Electrocardiogram

An electrocardiogram is not employed in the diagnosis of Turner syndrome.

X-ray

A x-ray may be used to diagnose cardiac and skeletal abnormalities.

Echocardiography and Ultrasound

Prenatal ultrasounds my show a left-sided cardiac defect, renal anomalies, growth retardation, relatively short limbs, fetal edema, cystic hygroma, polyhydramnios and brachycephaly. Echocardiographies and renal ultrasounds help detect structural defects.

CT scan

Simple CTs or CT angiographies are helpful in screening/detecting the following cardiac abnormalities.

MRI

Cardiac MRIs are helpful in screening/detecting the following cardiac abnormalities and functional MRIs have been used to study neural pathways responsible for poor visual spatial skills and executive function.

Other Imaging Findings

There are no other imaging findings associated with Turner syndrome.

Other Diagnostic Studies

The diagnostic study of choice for the diagnosis of Turner syndrome is karyotype analysis of 30 blood lymphocytes. Findings may include the classic 45 XO karyotype, mosaicism and structural anomalies like isochromosomes or ring chromosomes.

Treatment

Medical Therapy

Interventions

Surgery

Primary Prevention

Secondary Prevention

There are no established measures for the secondary prevention of Turner Syndrome. Secondary prevention is aimed at preventing complications of Turner syndrome. This involves frequent screening of complications.

References


Template:WikiDoc Sources