RESUMO
Next-generation sequencing strategies have resulted in mutation detection rates of 21% to 61% in small cohorts of patients with microphthalmia, anophthalmia and coloboma (MAC), but despite progress in identifying novel causative genes, many patients remain without a genetic diagnosis. We studied a cohort of 19 patients with MAC who were ascertained from a population with high rates of consanguinity. Using single nucleotide polymorphism (SNP) arrays and whole exome sequencing (WES), we identified one pathogenic variant in TENM3 in a patient with cataracts in addition to MAC. We also detected novel variants of unknown significance in genes that have previously been associated with MAC, including KIF26B, MICU1 and CDON, and identified variants in candidate genes for MAC from the Wnt signaling pathway, comprising LRP6, WNT2B and IQGAP1, but our findings do not prove causality. Plausible variants were not found for many of the cases, indicating that our current understanding of the pathogenesis of MAC, a highly heterogeneous group of ocular defects, remains incomplete.
Assuntos
Anoftalmia/genética , Moléculas de Adesão Celular/genética , Coloboma/genética , Proteínas de Membrana/genética , Microftalmia/genética , Proteínas do Tecido Nervoso/genética , Proteínas Supressoras de Tumor/genética , Anoftalmia/patologia , Proteínas de Ligação ao Cálcio/genética , Proteínas de Transporte de Cátions/genética , Coloboma/patologia , Consanguinidade , Exoma/genética , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Cinesinas/genética , Masculino , Microftalmia/patologia , Proteínas de Transporte da Membrana Mitocondrial/genética , Mutação/genética , Polimorfismo de Nucleotídeo Único/genética , Sequenciamento do ExomaRESUMO
The Integrator complex subunit 1 (INTS1) is a component of the integrator complex that comprises 14 subunits and associates with RPB1 to catalyze endonucleolytic cleavage of nascent snRNAs and assist RNA polymerase II in promoter-proximal pause-release on protein-coding genes. We present five patients, including two sib pairs, with biallelic sequence variants in INTS1. The patients manifested absent or severely limited speech, an abnormal gait, hypotonia and cataracts. Exome sequencing revealed biallelic variants in INTS1 in all patients. One sib pair demonstrated a missense variant, p.(Arg77Cys), and a frameshift variant, p.(Arg1800Profs*20), another sib pair had a homozygous missense variant, p.(Pro1874Leu), and the fifth patient had a frameshift variant, p.(Leu1764Cysfs*16) and a missense variant, p.(Leu2164Pro). We also report additional clinical data on three previously described individuals with a homozygous, loss of function variant, p.(Ser1784*) in INTS1 that shared cognitive delays, cataracts and dysmorphic features with these patients. Several of the variants affected the protein C-terminus and preliminary modeling showed that the p.(Pro1874Leu) and p.(Leu2164Pro) variants may interfere with INTS1 helix folding. In view of the cataracts observed, we performed in-situ hybridization and demonstrated expression of ints1 in the zebrafish eye. We used Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas9 to make larvae with biallelic insertion/deletion (indel) variants in ints1. The mutant larvae developed typically through gastrulation, but sections of the eye showed abnormal lens development. The distinctive phenotype associated with biallelic variants in INTS1 points to dysfunction of the integrator complex as a mechanism for intellectual disability, eye defects and craniofacial anomalies.
Assuntos
Catarata/genética , Anormalidades Craniofaciais/genética , Deficiências do Desenvolvimento/genética , Proteína Wnt1/genética , Adolescente , Adulto , Animais , Catarata/fisiopatologia , Criança , Pré-Escolar , Anormalidades Craniofaciais/fisiopatologia , Deficiências do Desenvolvimento/fisiopatologia , Feminino , Mutação da Fase de Leitura/genética , Gastrulação/genética , Humanos , Lactente , Cristalino/crescimento & desenvolvimento , Cristalino/patologia , Masculino , Mutação de Sentido Incorreto/genética , Linhagem , Dobramento de Proteína , Sequenciamento do Exoma , Proteína Wnt1/química , Adulto Jovem , Peixe-Zebra/genéticaRESUMO
BACKGROUND: Both circulating tumour cell (CTC) and total circulating cell-free DNA (ccfDNA) predict cancer patient prognosis. However, no study has explored the prognostic value of the combined use of CTC and ccfDNA. We aimed to investigate individual and joint effects of CTC and ccfDNA on clinical outcomes of metastatic breast cancer (MBC) patients. METHODS: We collected 227 blood samples from 117 MBC patients. CTCs were enumerated using the CellSearch System. ccfDNAs were quantified by quantitative real-time polymerase chain reaction and Qubit fluorometer. The individual and joint effects of CTC and ccfDNA levels on patient progression-free survival (PFS) and overall survival (OS) were analysed using Cox proportional hazards models. RESULTS: Compared to patients with <5 CTCs, patients with ≥5 CTCs had a 2.58-fold increased risk of progression and 3.63-fold increased risk of death. High level of ccfDNA was associated with a 2.05-fold increased risk of progression and 3.56-fold increased risk of death. These associations remained significant after adjusting for other important clinical covariates and CTC/ccfDNA levels. CTC and ccfDNA levels had a joint effect on patient outcomes. Compared to patients with low levels of both CTC and ccfDNA, those with high levels of both markers exhibited a >17-fold increased death risk (P < 0.001). Moreover, longitudinal analysis of 132 samples from 22 patients suggested that the inconsistency between CTC level and outcome in some patients could possibly be explained by ccfDNA level. CONCLUSIONS: CTC and total ccfDNA levels were individually and jointly associated with PFS and OS in MBC patients.
Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/patologia , DNA Tumoral Circulante/genética , Células Neoplásicas Circulantes/patologia , Adulto , Idoso , Neoplasias da Mama/sangue , Neoplasias da Mama/mortalidade , Contagem de Células , DNA Tumoral Circulante/sangue , Progressão da Doença , Feminino , Humanos , Biópsia Líquida , Pessoa de Meia-Idade , Metástase Neoplásica , Valor Preditivo dos Testes , Intervalo Livre de Progressão , Reação em Cadeia da Polimerase em Tempo Real , Medição de Risco , Fatores de Risco , Fatores de TempoRESUMO
Blepharocheilodontic syndrome (BCDS) consists of lagophthalmia, ectropion of the lower eyelids, distichiasis, euryblepharon, cleft lip/palate and dental anomalies and has autosomal dominant inheritance with variable expression. We identified heterozygous variants in two genes of the cadherin-catenin complex, CDH1, encoding E-cadherin, and CTNND1, encoding p120 catenin delta1 in 15 of 17 BCDS index patients, as was recently described in a different publication. CDH1 plays an essential role in epithelial cell adherence; CTNND1 binds to CDH1 and controls the stability of the complex. Functional experiments in zebrafish and human cells showed that the CDH1 variants impair the cell adhesion function of the cadherin-catenin complex in a dominant-negative manner. Variants in CDH1 have been linked to familial hereditary diffuse gastric cancer and invasive lobular breast cancer; however, no cases of gastric or breast cancer have been reported in our BCDS cases. Functional experiments reported here indicated the BCDS variants comprise a distinct class of CDH1 variants. Altogether, we identified the genetic cause of BCDS enabling DNA diagnostics and counseling, in addition we describe a novel class of dominant negative CDH1 variants.
Assuntos
Antígenos CD/genética , Caderinas/genética , Cateninas/genética , Fenda Labial/genética , Fissura Palatina/genética , Ectrópio/genética , Mutação , Anormalidades Dentárias/genética , Adolescente , Adulto , Animais , Antígenos CD/metabolismo , Caderinas/metabolismo , Cateninas/metabolismo , Adesão Celular , Criança , Pré-Escolar , Fenda Labial/patologia , Fissura Palatina/patologia , Ectrópio/patologia , Feminino , Humanos , Células MCF-7 , Masculino , Ligação Proteica , Anormalidades Dentárias/patologia , Peixe-Zebra , delta CateninaRESUMO
Sequence variants in CRB2 cause a syndrome with greatly elevated maternal serum alpha-fetoprotein and amniotic fluid alpha-fetoprotein levels, cerebral ventriculomegaly and renal findings similar to Finnish congenital nephrosis. All reported patients have been homozygotes or compound heterozygotes for sequence variants in the Crumbs, Drosophila, Homolog of, 2 (CRB2) genes. Variants affecting CRB2 function have also been identified in four families with steroid resistant nephrotic syndrome, but without any other known systemic findings. We ascertained five, previously unreported individuals with biallelic variants in CRB2 that were predicted to affect function. We compiled the clinical features of reported cases and reviewed available literature for cases with features suggestive of CRB2-related syndrome in order to better understand the phenotypic and genotypic manifestations. Phenotypic analyses showed that ventriculomegaly was a common clinical manifestation (9/11 confirmed cases), in contrast to the original reports, in which patients were ascertained due to renal disease. Two children had minor eye findings and one was diagnosed with a B-cell lymphoma. Further genetic analysis identified one family with two affected siblings who were both heterozygous for a variant in NPHS2 predicted to affect function and separate families with sequence variants in NPHS4 and BBS7 in addition to the CRB2 variants. Our report expands the clinical phenotype of CRB2-related syndrome and establishes ventriculomegaly and hydrocephalus as frequent manifestations. We found additional sequence variants in genes involved in kidney development and ciliopathies in patients with CRB2-related syndrome, suggesting that these variants may modify the phenotype.