Dataset Information

Rothmund-Thomson syndrome type 1 caused by biallelic ANAPC1 gene mutations.

ABSTRACT:

Background

Rare syndromic skin disorders may represent a diagnostic challenge.

Aims

We report a unique case associating cutaneous manifestations and developmental delay.

Materials & methods

The affected 14 months old boy had poikiloderma, facial dysmorphism with deep-set eyes, atrichia, as well as nail dysplasia and non-descended testes. In addition, his psychomotor development was delayed. Exome sequencing and molecular karyotyping via array-CGH (oligo-array, 180k Agilent, design 22060) were performed.

Results

Mutations in RECQL4 (found in patients with RTS2) were first excluded. In the ANAPC1 gene, a novel combination of a recurrent intronic mutation (c.2705-198C>T) and a deletion of the second ANAPC1 allele was detected, thus confirming the clinical diagnosis of RTS1. The deletion on chromosome 2q13 comprised further genes and spanned 1,7 megabases. Heterozygous deletions in this region are known as 2q13 microdeletion syndrome and are associated with developmental delay, autism and facial dysmorphism.

Discussion

The genetic findings most probably explain both, the RTS1 features and the developmental delay. Genetic diagnosis in RTS is indispensable to confirm the specific subtype and its associated risks: juvenile cataracts are features of RTS1 (ANAPC1 gene), whereas a high risk of osteosarcoma is part of RTS2 (RECQL4 gene). Thus, the patient described here is at high risk for the development of juvenile cataracts and requires regular ophthalmologic examination.

Conclusion

This case report underlines the necessity of thorough clinical diagnosis prior to genetic diagnosis of RTS1, since the recurrent intronic ANAPC1 mutation is otherwise missed.

SUBMITTER: Zirn B

PROVIDER: S-EPMC9060067 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature

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Publications

Rothmund-Thomson syndrome type 1 caused by biallelic ANAPC1 gene mutations.

Zirn B B Bernbeck U U Alt K K Oeffner F F Gerhardinger A A Has C C

Skin health and disease 20210212 1

<h4>Background</h4>Rare syndromic skin disorders may represent a diagnostic challenge.<h4>Aims</h4>We report a unique case associating cutaneous manifestations and developmental delay.<h4>Materials & methods</h4>The affected 14 months old boy had poikiloderma, facial dysmorphism with deep-set eyes, atrichia, as well as nail dysplasia and non-descended testes. In addition, his psychomotor development was delayed. Exome sequencing and molecular karyotyping via array-CGH (oligo-array, 180k Agilent, ...[more]

PMID: 35664819

Similar Datasets

Project description:Rothmund-Thomson syndrome (RTS) is a genodermatosis presenting with a characteristic facial rash (poikiloderma) associated with short stature, sparse scalp hair, sparse or absent eyelashes and/or eyebrows, juvenile cataracts, skeletal abnormalities, radial ray defects, premature aging and a predisposition to cancer. The prevalence is unknown but around 300 cases have been reported in the literature so far. The diagnostic hallmark is facial erythema, which spreads to the extremities but spares the trunk, and which manifests itself within the first year and then develops into poikiloderma. Two clinical subforms of RTS have been defined: RTSI characterised by poikiloderma, ectodermal dysplasia and juvenile cataracts, and RTSII characterised by poikiloderma, congenital bone defects and an increased risk of osteosarcoma in childhood and skin cancer later in life. The skeletal abnormalities may be overt (frontal bossing, saddle nose and congenital radial ray defects), and/or subtle (visible only by radiographic analysis). Gastrointestinal, respiratory and haematological signs have been reported in a few patients. RTS is transmitted in an autosomal recessive manner and is genetically heterogeneous: RTSII is caused by homozygous or compound heterozygous mutations in the RECQL4 helicase gene (detected in 60-65% of RTS patients), whereas the aetiology in RTSI remains unknown. Diagnosis is based on clinical findings (primarily on the age of onset, spreading and appearance of the poikiloderma) and molecular analysis for RECQL4 mutations. Missense mutations are rare, while frameshift, nonsense mutations and splice-site mutations prevail. A fully informative test requires transcript analysis not to overlook intronic deletions causing missplicing. The diagnosis of RTS should be considered in all patients with osteosarcoma, particularly if associated with skin changes. The differential diagnosis should include other causes of childhood poikiloderma (including dyskeratosis congenita, Kindler syndrome and Poikiloderma with Neutropaenia), other rare genodermatoses with prominent telangiectasias (including Bloom syndrome, Werner syndrome and Ataxia-telangiectasia) and the allelic disorders, RAPADILINO syndrome and Baller-Gerold syndrome, which also share some clinical features. A few mutations recur in all three RECQL4 diseases. Genetic counselling should be provided for RTS patients and their families, together with a recommendation for cancer surveillance for all patients with RTSII. Patients should be managed by a multidisciplinary team and offered long term follow-up. Treatment includes the use of pulsed dye laser photocoagulation to improve the telangiectatic component of the rash, surgical removal of the cataracts and standard treatment for individuals who develop cancer. Although some clinical signs suggest precocious aging, life expectancy is not impaired in RTS patients if they do not develop cancer. Outcomes in patients with osteosarcoma are similar in RTS and non-RTS patients, with a five-year survival rate of 60-70%. The sensitivity of RTS cells to genotoxic agents exploiting cells with a known RECQL4 status is being elucidated and is aimed at optimizing the chemotherapeutic regimen for osteosarcoma.

Dataset Information

Rothmund-Thomson syndrome type 1 caused by biallelic ANAPC1 gene mutations.

Background

Aims

Materials & methods

Results

Discussion

Conclusion

Publications

Rothmund-Thomson syndrome type 1 caused by biallelic ANAPC1 gene mutations.

Similar Datasets

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