Dyskeratosis congenita: Difference between revisions

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{{Dyskeratosis congenita}}
{{Dyskeratosis congenita}}
'''For patient information, click [[Dyskeratosis congenita (patient information)|here]].'''
{{CMG}} {{AE}} {{RT}}
{{CMG}} {{AE}} {{RT}}


'''''Synonyms and keywords''''': Zinsser-Cole-Engman syndrome; X-linked dyskeratosis congenita; Cole-Rauschkolb-Toomey syndrome; DKCX
{{SK}} Cole-Rauschkolb-Toomey syndrome; DKCX; X-linked dyskeratosis congenita; Zinsser-Cole-Engman syndrome; Zinsser-Engman-Cole syndrome


==[[Dyskeratosis congenita overview|Overview]]==
==[[Dyskeratosis congenita overview|Overview]]==
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==[[Dyskeratosis congenita causes| Causes]]==
==[[Dyskeratosis congenita causes| Causes]]==


==Epidemiology and Demographics==
==[[Dyskeratosis congenita differential diagnosis|Differentiating Dyskeratosis Congenita from other Diseases]]==
'''Age''': The mucocutaneous features of DKC typically develop between ages 5 and 15 years.  The median age of onset of the peripheral cytopenia is 10 years.
 
==[[Dyskeratosis congenita epidemiology and demographics|Epidemiology and Demographics]]==


'''Gender''': The male-to-female ratio is approximately 3:1.
==[[Dyskeratosis congenita risk factors|Risk Factors]]==


==Natural history, Complications and Prognosis==
==[[Dyskeratosis congenita screening|Screening]]==
Complications include:
* [[Conjunctivitis]], [[blepharitides]], lacrimal duct stenosis, and [[pterygium]]
* [[Mandibular hypoplasia]], [[osteoporosis]], [[avascular necrosis]], and [[scoliosis]].
* [[Cirrhosis]]
* Bone marrow failure - infections, bleeding
* Pulmonary fibrosis
* [[Dysphagia]], [[dysuria]], [[phimosis]], and [[epiphora]] - due to constriction and stenosis can occur at the sites of [[leukoplakia]]
* Increased risk of malignancy - increased prevalence of malignant mucosal neoplasms, particularly squamous cell carcinoma of the mouth, nasopharynx, esophagus, rectum, vagina, or cervix.  These often occur within sites of leukoplakia.  The prevalence of squamous cell carcinoma of the skin is also increased.
* [[Death]] - due to infections, bleeding


Prognosis of the disease is poor with a mean survival of 30 years.  Prognosis is worse for X-linked and autosomal recessive forms compared to autosomal dominant form.
==[[Dyskeratosis congenita natural history, complications and prognosis|Natural History, Complications and Prognosis]]==


==Diagnosis==
==Diagnosis==
===Symptoms===
[[Dyskeratosis congenita history and symptoms|History and Symptoms]] | [[Dyskeratosis congenita physical examination|Physical Examination]] | [[Dyskeratosis congenita laboratory findings|Laboratory Findings]] | [[Dyskeratosis congenita electrocardiogram|Electrocardiogram]] | [[Dyskeratosis congenita x ray|X Ray]] | [[Dyskeratosis congenita CT|CT]] | [[Dyskeratosis congenita MRI|MRI]] | [[Dyskeratosis congenita echocardiography or ultrasound|Echocardiography or Ultrasound]] | [[Dyskeratosis congenita other imaging findings|Other Imaging Findings]] | [[Dyskeratosis congenita other diagnostic studies|Other Diagnostic Studies]]
Patients with DKC complain of
* Cutaneous pigmentation - hyper or hypo-pigmentation
* Premature graying of hair
* [[Dystrophy]] of the [[nail (anatomy)|nail]]s - ridging and longitudinal splitting
* [[Leukoplakia]] of the oral mucosa (patches on the tongue and inside the mouth)
* Continuous/excess [[lacrimation]] (due to [[atresia]] of the [[lacrimal duct]]s)
* [[Decreased libido]] (due to [[testicular atrophy]] in the male carriers).
 
===Physical Examination===
The triad of reticulated [[hyperpigmentation]] of the skin, [[nail dystrophy]], and [[leukoplakia]] characterizes DKC.  The syndrome is clinically heterogeneous; in addition to the diagnostic mucocutaneous features and [[bone marrow]] failure, affected individuals can have a variety of other clinical features.
 
'''Skin''':
* Abnormal skin pigmentation - tan to gray hyperpigmented or hypopigmented macules and patches in a mottled or reticulated pattern.  Reticulated pigmentation occurs in approximately 90% of patients.
* Poikilodermatous changes with [[atrophy]] and [[telangiectasia]] are common.
* [[Alopecia]] of the scalp, eyebrows, and eyelashes
* [[Premature graying]] of the hair
* [[Hyperhidrosis]]
* [[Hyperkeratosis]] of the palms and soles
* [[Adermatoglyphia]] (loss of dermal ridges on fingers and toes).
 
The cutaneous presentation may clinically and histologically resemble graft versus host disease.  The typical distribution involves the sun-exposed areas, including the upper trunk, neck, and face.
 
'''Extremities''':
* [[Nail dystrophy]] (ridging and longitudinal splitting) - seen in approximately 90% of patients, with fingernail involvement often preceding toenail involvement.
* Absent nails - in advanced disease.
 
'''Mucosal findings''':
* [[Mucosal leukoplakia]] - occurs in approximately 80% of patients and typically involves the buccal mucosa, tongue, and oropharynx.
Patients also may have an increased prevalence and severity of [[periodontal disease]].
Other mucosal sites may be involved (e.g., esophagus, urethral meatus, glans penis, lacrimal duct, conjunctiva, vagina, anus).
 
'''Respiratory''':
* [[Rales]] are heard in those having [[pulmonary fibrosis]].
 
'''Neurologic''':
* Low IQ
* Patients may have learning difficulties and [[mental retardation]].
 
'''Eye''':
* [[Excessive tearing]]
* [[Red eyes]]
 
'''Abdomen''':
* [[Esophageal webs]]
* [[Hepatosplenomegaly]]
 
'''Genitourinary system findings:''':
* [[Hypospastic testes]] (small testis),
* [[Hypospadias]]
* [[Ureteral stenosis]]
 
'''Female carriers''':
 
Female carries of DKC may have subtle clinical features.  One study showed that 3 of 20 female carriers had clinical features that included a single dystrophic nail, a patch of [[hypopigmentation]], or mild [[leukoplakia]].
 
===Lab tests===
* Complete blood counts and differential counts
* Stool tests for occult blood
* [[Pulmonary function tests]]
 
===X-ray===
* X-ray head shows calcification of [[basal ganglia]]
* Chest x-ray for [[pulmonary fibrosis]]


==Treatment==
==Treatment==
Recent research has used [[Induced pluripotent stem cell|induced pluripotent stem cells]] to study the disease mechanisms in humans, and discovered that the repgrogramming of somatic cells restores telomere elongation in dyskeratosis congenita cells despite the genetic lesions that affect telomerase.  The reprogrammed DC cells were able to overcome a critical limitation in [[Telomerase RNA component|TERC]] (Telomerase RNA component) levels and restored function (telomere maintenance and self-renewal).  Therapeutically, methods aimed at increasing TERC expression could prove beneficial in DC patients. <ref name="pmid20164838">{{cite journal | author = Agarwal ''et al'' | title = : Telomere elongation in induced pluripotent stem cells from dyskeratosis congenita patients | journal = Nature | volume = 464 | issue = | pages = 292-296 | year = 2010 | month = | pmid = 20164838 | doi = 10.1038/nature08792 }}</ref>
[[Dyskeratosis congenita medical therapy|Medical Therapy]] | [[Dyskeratosis congenita surgery|Surgery]] | [[Dyskeratosis congenita primary prevention|Primary Prevention]] | [[Dyskeratosis congenita secondary prevention|Secondary Prevention]] | [[Dyskeratosis congenita cost-effectiveness of therapy|Cost-Effectiveness of Therapy]] | [[Dyskeratosis congenita future or investigational therapies|Future or Invesetigational Therapies]]


== References ==
==Case Studies==
{{reflist|2}}
[[Dyskeratosis congenita case study one|Case #1]]


==External links==
==External Links==
*[http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=gene&part=dkc GeneReviews/NCBI/NIH/UW entry on Dyskeratosis Congenita]
* [http://www.marrowfailure.cancer.gov/index.html Dyskeratosis Congenita research study of Inherited Bone Marrow Failure Syndromes (IBMFS) ]
* [http://www.marrowfailure.cancer.gov/index.html Dyskeratosis Congenita research study of Inherited Bone Marrow Failure Syndromes (IBMFS) ]



Latest revision as of 17:41, 15 February 2015

Dyskeratosis congenita Microchapters

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Overview

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Pathophysiology

Causes

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Epidemiology and Demographics

Risk Factors

Screening

Natural History, Complications and Prognosis

Diagnosis

History and Symptoms

Physical Examination

Laboratory Findings

Electrocardiogram

X Ray

CT

MRI

Echocardiography or Ultrasound

Other Imaging Findings

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Treatment

Medical Therapy

Surgery

Primary Prevention

Secondary Prevention

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Case #1

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

Synonyms and keywords: Cole-Rauschkolb-Toomey syndrome; DKCX; X-linked dyskeratosis congenita; Zinsser-Cole-Engman syndrome; Zinsser-Engman-Cole syndrome

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Dyskeratosis Congenita from other Diseases

Epidemiology and Demographics

Risk Factors

Screening

Natural History, Complications and Prognosis

Diagnosis

History and Symptoms | Physical Examination | Laboratory Findings | Electrocardiogram | X Ray | CT | MRI | Echocardiography or Ultrasound | Other Imaging Findings | Other Diagnostic Studies

Treatment

Medical Therapy | Surgery | Primary Prevention | Secondary Prevention | Cost-Effectiveness of Therapy | Future or Invesetigational Therapies

Case Studies

Case #1

External Links

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