Genetic landscape of RASopathies in Chinese: Three decades' experience in Hong Kong.

RASopathies are a group of genetic disorders due to dysregulation of the RAS-MAPK signaling pathway, which is important in regulating cell growth, proliferation, and differentiation. These include Noonan syndrome (NS), Noonan syndrome with multiple lentigines (NSML), cardiofaciocutaneous (CFC) syndrome, and Costello syndrome (CS), clinical manifestations include growth retardation, developmental delay, cardiac defects, and specific dysmorphic features. There were abundant publications describing the genotype and phenotype from the Western populations. However, detailed study of RASopathies in Chinese population is lacking. We present here the largest cohort of RASopathies ever reported in Chinese populations, detailing the mutation spectrum and clinical phenotypes of these patients. The Clinical Genetic Service, Department of Health, and Queen Mary Hospital are tertiary referral centers for genetic disorders in Hong Kong. We retrospectively reviewed all the genetically confirmed cases of RASopathies, including NS, NSML, CFC syndrome, and CS, over the past 29 years (from 1989 to 2017). Analyses of the mutation spectrum and clinical phenotypes were performed. One hundred and ninety-one ethnic Chinese patients with genetically confirmed RASopathies were identified, including 148 patients with NS, 23 NSML, 12 CFC syndrome, and eight CS. We found a lower incidence of hypertrophic cardiomyopathy in individuals with NSML (27.3%), and NS caused by RAF1 mutations (62.5%). Another significant finding was for those NS patients with myeloproliferative disorder, the mutations fall within Exon 3 of PTPN11 but not only restricted to the well-known hotspots, that is, p.Asp61 and p.Thr731, which suggested that re-evaluation of the current tumor surveillance recommendation maybe warranted.

A 'Full House' Glomerulopathy in a Patient with Multiple Lentigines Syndrome: A Case Report / Glomerulopatía 'full house' en un paciente con síndrome de lentigos múltiples: un reporte de caso

ABSTRACT Multiple lentigines syndrome (MLS) is an autosomal dominant disease which is usually diagnosed clinically by the presence of characteristic features. The molecular genetic testing is an adjuvant diagnostic tool to identify the mutation of particular genes such as PTPN11 genes, RAF1, BRAF or MAP2K1 genes. This syndrome was formerly known as LEOPARD syndrome or Noonan syndrome with multiple lentigines. 'LEOPARD syndrome ' is an acronym of characteristic features (Lentigines, Electrocardiographic conduction abnormalities, Ocular hypertelorism, Pulmonary stenosis, Abnormalities of the genitalia, Retardation of growth, and Deafness). There was no previous case report about any glomerulonephropathy in association with MLS. We present a case of a patient with MLS with recurrent nephrotic syndrome who was found to have histologic evidence of 'full house ' glomerulopathy.

RESUMEN El síndrome de lentigos múltiples (SLM) es una enfermedad autosómica dominante que de modo general se diagnostica clínicamente por la presencia de rasgos característicos. La prueba genética molecular es una herramienta de diagnóstico auxiliar utilizada para identificar la mutación de genes específicos tales como los genes PTPN11, RAF1, BRAF, o los genes MAP2K1. Este síndrome se conocía anteriormente como síndrome del leopardo o síndrome de Noonan con múltiples lentigos. El síndrome toma su nombre del acrónimo en inglés LEOPARD, que describe sus rasgos característicos (L lentigos; E conducción electrocardiográfica de las anormalidades; O hipertelorismo ocular; P estenosis pulmonar; A anormalidades de los genitales; R retardo del crecimiento; y D deafness, 'sordera ' en inglés), y que fuera introducido por Gorlin et al en 1969. No existía ningún reporte de caso anterior sobre glomerulonefropatía asociada con SLM. Presentamos el caso de un paciente con SLM con síndrome nefrótico recurrente en el que se halló evidencia histológica de glomerulopatía 'full house'.

A Case of Multiple Lentigines Sydrome with a Family History of Multiple Lentigines / 대한피부과학회지

Multiple lentigines syndrome is an autosomal dominant disorder of variable penetrance and expressivity. LEOPARD has been used to describe the main features of the syndrome, including lentigines, electrocardiographic abnormalities, ocular hypertelorism, pulmonary stenosis, abnormalities of genitalia, retardation of growth and deafness. We describe a case of multiple lentigines syndrome with a family history of multiple lentigines. A 15-year-old boy presented with multiple brown macules and patches on the whole body, which had developed since the age of 3. He also had hypertrophic cardiomyopathy, EKG abnormalities and retarded growth. His maternal grandfather, maternal uncle and mother also presented with multiple brown macules scattered over the body. The biopsy specimen taken from the macule revealed elongated rete ridges, increased melanin deposition and increased number of melanocytes.

A Case of Multiple Lentigines Syndrome

The multiple lentigines syndrome or LEOPARD syndrome is an autosomal dominantly inherited disorder with a variety of abnormalities and a familial occurrence. This syndrome is characterized by the presence of numerous dark brown macules on the skin but not the mucous surface, and by a marked increase in the number of lentigines from birth to puberty. The eponym LEOPARD stands for lentigines, EKG abnormalities, ocular hypertelorism, pulmonary stenosis, abnormalities of the genitalia, retardation of growth and deafness. We report a case of multiple lentigines syndrome in 7-year-old boy. He had numerous pinhead to pea sized, dark brownish macules scattered on the entire body and also had pulmonary stenosis, EKG abnormality, ocular hypertelorism and right exotropia. Interestingly, he also had a labial melanotic macule on the lower lip, which is usually spared in the multiple lentigines syndrome. Histologically, the biopsy specimen taken from the macule revealed an elongation of rete ridges, an increase of melanin pigments in the basal layer and mild inflammatory infiltrates intermingled with the melanophages in the upper dermis.