Intracranial calcifications and dyskeratosis congenita

We describe two brothers with dyskeratosis congenita and intracranial calcifications. The calcifications were massive, approximately symmetric, and showed a predilection for the basal ganglia and dentate nuclei. No underlying causes for this finding were identified. Idiopathic familial intracranial calcification of this type has been described, but an association with dyskeratosis congenita has not previously been observed.     

Dyskeratosis Congenita Associated with Elevated Fetal Hemoglobin, X-Linked Ocular Albinism, and Juvenile-Onset Diabetes Mellitus

An 11-year-old boy had dyskeratosis congenita, elevated fetal hemoglobin level, X-linked ocular albinism, and juvenile-onset diabetes mellitus. A review of the international literature revealed that elevated fetal hemoglobin has been noted in 15 reported cases of dyskeratosis congenita. It is a previously unrecognized, commonly associated finding in dyskeratosis congenita that may provide insight into the location and function of the gene for dyskeratosis congenita.     

Uncommon vascular naevi associated with focal acantholytic dyskeratosis

Cutis marmorata telangiectatica congenita and vascular twin naevi are rare vascular anomalies in which focal acantholytic dyskeratosis is usually not observed. We describe a 44-year-old-man who presented for evaluation of skin lesions that had been present since birth. Physical examination revealed anaemic macules adjacent to a naevus telangiectaticus on the chest. Naevus anaemicus was also seen on the shoulders, arms, and left leg. There was bluish-reddish reticulate marking of the skin and cutaneous atrophy. Shortening and hypoplasia of the left leg was observed. Histologic examination of two biopsy specimens revealed focal acantholytic dyskeratosis. In vivo confocal laser scanning microscopy showed dilated capillaries and vessels of the upper dermal plexus in the telangiectatic and decreased capillary blood flow in the anaemic skin sites. The findings were consistent with a diagnosis of cutis marmorata telangiectatica congenita, vascular twin naevi, and incidental focal acantholytic dyskeratosis. The particularities of the present case are the following: firstly, the association of two rare vascular anomalies to which the genetic concept of mosaicism can be applied; secondly, the occurrence of incidental focal acantholytic dyskeratosis in sites of vascular naevi.     

Cytogenetic abnormalities in dyskeratosis congenita—report of five cases

Five patients with dyskeratosis congenita arc described. The cytogenetic studies showed varying frequencies of chromosomal abnormalities which included gaps, chromatid breaks and pulverizations, ranging from 4 to 22%. These findings suggest that chromosomal breakage may be of fundamental importance in the etiology of dyskeratosis congenita and it could represent a genetic marker for the disease.     

A case of dyskeratosis congenita associated with impaired DNA repair as shown by the comet assay.

An 18-year old boy with dyskeratosis congenita is presented. To examine the DNA metabolism of our patient, we applied the comet assay, a simple, quick and sensitive method that so far has not been used in this disease. After exposure to UVB, cells originating from the patient present abnormal DNA repair localized in the late step. We consider that such repair deficiency could be related to susceptibility to cancer. The comet assay seems to be a good procedure to investigate dyskeratosis congenita or other genodermatoses.     

先天性角化不良的一个新的基因突变

目的 检测一例先天性角化不良(DKC)患者DKC1基因的突变情况。方法 采用PCR技术扩增DKC1基因的15个外显子,然后采用变性高效液相色谱(DHPLC)技术进行基因突变筛查,对筛查结果异常的外显子进行DNA测序:基因突变的验证在100例无相关遗传性疾病的无关男性中进行。结果 患者DKC1基因的第12号外显子呈异常的DHPLC洗脱峰,家庭其他成员及正常群体对照未见此异常洗脱峰。测序结果显示患者DKC1基因第12外显子的1236位碱基由G→T,导致W412C突变,家庭其他成员及正常群体对照均未见此突变。结论 我们检测到的患者DKC1基因W412C是一个新的散发性突变,它可能导致患者先天性角化不良。     

先天性角化不良6例

报道6例先天性角化不良，均有典型的临床表现，即皮肤异色症样皮损、指趾甲萎缩脱落和粘膜白斑等。其中1例伴有再生障碍性贫血。5例患者的皮损曾行组织病理学检查，其改变均与本病相符。     

Dermatological manifestations of inherited cancer syndromes in children

Various cutaneous signs presenting in childhood, for example café-au-lait macules, may have systemic cancer associations. Indeed, this may be the first manifestation of the underlying cancer predisposition. The syndromes covered in this review fall into four main categories: (i) DNA damage processing defects including Fanconi anaemia, ataxia telangiectasia, Bloom syndrome, Rothmund-Thomson syndrome, constitutional mismatch repair defects and xeroderma pigmentosum; (ii) signalling pathway defects, including naevoid basal cell carcinoma and Costello syndromes; (iii) primary immunodeficiency syndromes; and (iv) syndromes that do not fit this molecular classification, such as X-linked dyskeratosis congenita. This review focuses on the dermatological findings of these conditions. Some of these conditions exhibit a milder heterozygous phenotype and this should be elicited in the family history. Where the dermatological findings are subtle, a targeted family history can provide clues towards making a diagnosis. Nondermatological features of each condition are summarized too, together with molecular testing strategies, which will direct genetic counselling and screening. This review will enable the dermatologist and other clinicians in the early recognition and molecular confirmation of underlying cancer-predisposing syndromes. This allows the possibility of surveillance and prevention strategies to be initiated in a timely manner, in affected children and other at-risk family members.     

Identification of a novel mutation and a de novo mutation in DKC1 in two Chinese pedigrees with Dyskeratosis congenita

Dyskeratosis congenita (DKC) is a rare and fatal congenital syndrome characterized by the triad of reticular skin pigmentation, nail dystrophy and mucosal leukoplakia, and the predisposition to bone marrow failure and malignancies. Mutations in DKC1 gene encoding dyskerin are responsible for the X-linked dyskeratosis congenita. Here we report mutation analysis of two Chinese pedigrees with dyskeratosis congenita. The 15 coding exons of DKC1 and their flanking regions were amplified from genomic DNA by PCR. DNA sequencing and restriction endonuclease digestion were used for mutation detection. Transition mutation of 1226C-->T (P409L) found in the first pedigree is a novel mutation. In the second pedigree, the proband's mother phenotypically normal carried a de novo transition mutation of 1058C-->T (A353 V) in one allele, and transmitted the mutant allele to her two sons who had typical manifestations of dyskeratosis congenita.     

Hoyeraal–Hreidarsson Syndrome: An Extremely Rare Dyskeratosis Congenita Phenotype

Hoyeraal–Hreidarsson syndrome is a rare telomere biology disorder that is recognized as a severe variant of dyskeratosis congenita. We present a Libyan boy with hematologic and neurologic abnormalities with typical dermatologic manifestations of dyskeratosis congenita. Death usually occurs before the age of 4 years as a result of pancytopenia or malignant transformation of mucocutaneous lesions. The boy presented survived longer than 5 years. Early recognition and appropriate genetic counseling are crucial because of the high mortality of this genetic disorder.     

Dyskeratosis congenita: delay in diagnosis and successful treatment of pancytopenia by bone marrow transplantation

Dyskeratosis congenita is an inherited disorder characterized by nail dystrophy, skin pigmentary changes, mucosal leukoplakia, pancytopenia and an increased incidence of malignancy. Because of a widely held view that the outcome of bone marrow transplantation in dyskeratosis congenita is poor, this treatment option is sometimes not considered when pancytopenia develops. We present a child currently doing well 3 years after bone marrow transplantation, and review the literature.     

Dyskeratosis congenita associated with three malignancies

Dyskeratosis congenita is a rare inheritable disorder characterized by abnormalities of the skin, nails and oral mucosa. Aplastic anaemia resulting from bone marrow hypoplasia is a frequent cause of death. Squamous cell carcinoma developing from leukoplakia and visceral malignancies are other complications of the disease. We report here a case of dyskeratosis congenita in a man who developed three neoplasias of different systems over a period of many years. Squamous cell carcinoma and gastric adenocarcinoma manifested 17 years after the man was diagnosed with Hodgkin's disease.     

Dyskeratosis congenita in a female

We report a 9-year-old Saudi girl with dyskeratosis congenita. In addition to the known manifestations of this disease, she also had the additional features of tufts of hairs on the limbs, and an early onset of keratinized basal cell papillomas on her trunk.     

Coats plus syndrome (cerebroretinal microangiopathy with calcifications and cysts‐1): A case report

We present a 6‐year‐old girl with skin hyperpigmentation, leukoplakia, and onychodystrophy, the classic mucocutaneous triad usually associated with dyskeratosis congenita. The patient also had premature graying of the hair, bone marrow failure, hepatitis, exudative retinopathy, osteopenia with multiple long bone fractures, and intracranial calcifications and brain cysts. Coats plus syndrome is a rare disease with a clinical and genetic overlap with dyskeratosis congenita. This disease is reviewed, with a focus on the pathogenesis of the genetic anomalies and its background as a telomere biology disorder.     

Dyskeratosis congenita in an adolescent girl with associated choanal atresia

Dyskeratosis congenita is a rare, progressive, degenerative disorder characterized by cutaneous and mucosal involvement in the first decade of life with malignant changes and bone marrow failure in the second and third decades. The primary inheritance pattern is X-linked recessive, with the majority of cases presenting in boys. We report dyskeratosis congenita in an adolescent girl with choanal atresia, a previously unreported association.     

Dyskeratosis congenita: a literature review

Dyskeratosis congenita is a rare hereditary disease that occurs predominantly in males and manifests clinically as the classic triad of reticulate hyperpigmentation, nail dystrophy and leukoplakia. It increases the risk of malignancy and other potentially lethal complications such as bone marrow failure, lung and liver diseases. Mutations in 19 genes are associated with dyskeratosis congenita, and a fifth of the pathogenic mutations are found in DKC1, the gene coding for dyskerin. This review aims to address the clinical and genetic aspects of the disease.     

The role of telomeres in the ageing of human skin

Skin is a self-renewing tissue that is required to go through extensive proliferation throughout the lifespan of an organism. Telomere shortening acts as a mitotic clock that prevents aberrant proliferation such as cancer. A consequence of this protection is cellular senescence and ageing. The telomerase enzyme complex maintains telomere length in germline cells and in cancer cells. Telomerase is also active in certain somatic cells such as those in the epidermis but is almost undetectable in the dermis. Increasing evidence indicates that telomerase plays a significant role in maintenance of skin function and proliferation. Mutations in telomerase component genes in the disease dyskeratosis congenita result in numerous epidermal abnormalities. Studies also indicate that telomerase activity in epidermal stem cells might have roles that go beyond telomere elongation. Telomeres in skin cells may be particularly susceptible to accelerated shortening because of both proliferation and DNA-damaging agents such as reactive oxygen species. Skin might present an accessible tissue for manipulation of telomerase activity and telomere length with the potential of ameliorating skin diseases associated with ageing.     

先天性角化不良1例

报告1例先天性角化不良。患者女,19岁,全身皮肤网状色素沉着,所有指趾甲营养不良和舌黏膜白斑。此外还伴发少汗、毛发稀少、龋齿、牙齿脱落、腭裂和轻度智力低下。血常规检查正常。腹部色素沉着区皮损组织病理检查显示真皮浅层较多噬色素细胞。     

Oral carcinoma in a young man: a case of dyskeratosis congenita

We report a 28-year-old male with a voluminous growth of the tongue, present for 6 months. The histological examination revealed a squamous cell carcinoma. The patient was also affected by oral leukoplakia, nail dystrophy, reticulated poikiloderma of the neck and hyperkeratosis of palms and soles. On the basis of clinical features and histological findings, as well as findings from the family, the diagnosis of dyskeratosis congenita (DKC) was made.