Dermatological manifestations, management, and care in RASopathies.

RASopathies are rare genetic disorders caused by germline pathogenic variants in genes belonging to the RAS/MAPK pathway, which signals cell proliferation, differentiation, survival and death. The dysfunction of such signaling pathway causes syndromes with overlapping clinical manifestations. Skin and adnexal lesions are the cardinal clinical signs of RASopathies, such as cardiofaciocutaneous syndrome, Noonan syndrome with multiple lentigines, formerly known as LEOPARD syndrome, Costello syndrome, neurofibromatosis (NF1), Legius syndrome, Noonan-like syndrome with loose anagen hair (NSLH) and Noonan syndrome. As NF1, one of the most common RASopathies, described in 1882, has its clinical features well delineated, we will focus on the dermatological diagnosis, management and care of non-NF1 RASopathies, which are less known and more recently described. Dermatological manifestations are important clinical diagnostic elements that can aid differential diagnosis among RASopathies. They can affect dermis and epidermis, causing pigmented lesions (melanocytic nevi, café-au-lait spots, and lentigines), hyperkeratosis (keratosis pilaris, ulerythema ophryogenes, and palmoplantar keratosis) or hyperplasia. To date there are rare known links to malignancy, but oftentimes skin lesions require close attention because they can highly affect quality of life.

Germline KRAS and BRAF mutations in cardio-facio-cutaneous syndrome.

Cardio-facio-cutaneous (CFC) syndrome is characterized by a distinctive facial appearance, heart defects and mental retardation. It phenotypically overlaps with Noonan and Costello syndrome, which are caused by mutations in PTPN11 and HRAS, respectively. In 43 individuals with CFC, we identified two heterozygous KRAS mutations in three individuals and eight BRAF mutations in 16 individuals, suggesting that dysregulation of the RAS-RAF-ERK pathway is a common molecular basis for the three related disorders.

Miliary osteoma of the face: a report of 4 cases and review of the literature.

Osteoma cutis (OC) is a rare disorder characterized by compact bone formation in the dermis and subcutaneous tissue. It is classified in primary and secondary forms according to the presence or absence of previous cutaneous lesions. Miliary osteoma of the face (MOF) is a form of primary OC that generally occurs in middle-aged and older adult women. We report 3 cases of typical MOF and one additional case in a black patient, which to our knowledge has not been described previously.

Cardio-facio-cutaneous syndrome: clinical features, diagnosis, and management guidelines.

Cardio-facio-cutaneous syndrome (CFC) is one of the RASopathies that bears many clinical features in common with the other syndromes in this group, most notably Noonan syndrome and Costello syndrome. CFC is genetically heterogeneous and caused by gene mutations in the Ras/mitogen-activated protein kinase pathway. The major features of CFC include characteristic craniofacial dysmorphology, congenital heart disease, dermatologic abnormalities, growth retardation, and intellectual disability. It is essential that this condition be differentiated from other RASopathies, as a correct diagnosis is important for appropriate medical management and determining recurrence risk. Children and adults with CFC require multidisciplinary care from specialists, and the need for comprehensive management has been apparent to families and health care professionals caring for affected individuals. To address this need, CFC International, a nonprofit family support organization that provides a forum for information, support, and facilitation of research in basic medical and social issues affecting individuals with CFC, organized a consensus conference. Experts in multiple medical specialties provided clinical management guidelines for pediatricians and other care providers. These guidelines will assist in an accurate diagnosis of individuals with CFC, provide best practice recommendations, and facilitate long-term medical care.

Molecular and clinical characterization of cardio-facio-cutaneous (CFC) syndrome: overlapping clinical manifestations with Costello syndrome.

Cardio-facio-cutaneous (CFC) syndrome is a multiple congenital anomaly/mental retardation syndrome characterized by heart defects, a distinctive facial appearance, ectodermal abnormalities and mental retardation. Clinically, it overlaps with both Noonan syndrome and Costello syndrome, which are caused by mutations in two genes, PTPN11 and HRAS, respectively. Recently, we identified mutations in KRAS and BRAF in 19 of 43 individuals with CFC syndrome, suggesting that dysregulation of the RAS/RAF/MEK/ERK pathway is a molecular basis for CFC syndrome. The purpose of this study was to perform comprehensive mutation analysis in 56 patients with CFC syndrome and to investigate genotype-phenotype correlation. We analyzed KRAS, BRAF, and MAP2K1/2 (MEK1/2) in 13 new CFC patients and identified five BRAF and one MAP2K1 mutations in nine patients. We detected one MAP2K1 mutation in three patients and four new MAP2K2 mutations in four patients out of 24 patients without KRAS or BRAF mutations in the previous study [Niihori et al., 2006]. No mutations were identified in MAPK3/1 (ERK1/2) in 21 patients without any mutations. In total, 35 of 56 (62.5%) patients with CFC syndrome had mutations (3 in KRAS, 24 in BRAF, and 8 in MAP2K1/2). No significant differences in clinical manifestations were found among 3 KRAS-positive patients, 16 BRAF-positive patients, and 6 MAP2K1/2-positive patients. Wrinkled palms and soles, hyperpigmentation and joint hyperextension, which have been commonly reported in Costello syndrome but not in CFC syndrome, were observed in 30-40% of the mutation-positive CFC patients, suggesting a significant clinical overlap between these two syndromes.

Estudo citogenético e molecular da síndrome cardiofaciocutânea / Cytogenetic and molecular studies on cardiofaciocutaneous syndrome

Objetivos: Verificar se pacientes com a síndrome Cardiofaciocutânea (CFC) apresentam microdeleções na região cromossômica 12q21.2q22, se os mesmos apresentam mutações de sentido trocado ou deleções intragênicas no gene PTPN11, e a presença de rearranjos teloméricos. Métodos: Foram utilizadas 12 sondas BAC, cobrindo o intervalo 12q21.2q22, para análise dessa regiãp por FISH, em 17 pacientes. Para o estudo do gene PTPN11, seqüenciamos toda a região codificante do mesmo, além das regiões de transição íntron/exon, em 10 pacientes. Amplificamos por PCR porções parcialmente sobreponíveis do cDNA dos mesmos pacientes para detectar possíveis deleções intragênicas. Utilizamos sondas subteloméricas para buscar rearranjos ou perdas cromossômicas em todos os cromossomos, em uma amostra de 10 pacientes. Resultados: Não foram encontradas microdeleções na região 12q21.2q22 nos pacientes com a síndrome CFC. Pacientes com a síndrome CFC não apresentam mutações de sentido trocado no gene PTPN11, nem micro ou macro deleções do mesmo na sua porção codificante. Pacientes com a síndrome CFC não apresentam rearranjos ou perdas nas regiões subteloméricas. Conclusões: A região cromossômica 12q21.2q22 não é região candidata para o gene da síndrome CFC. Fica molecularmente demostrado que a síndrome CFC e síndrome de Noonan são entidades com etiologias genéticas distintas. Finalmente, a síndrome CFC não é caracterízada por rearranjos ou perdas subteioméricas