Diagnóstico prenatal y array-CGH II: gestaciones de bajo riesgo / Array-CGH in prenatal diagnosis II: low-risk pregnancies

Recientemente, la tecnología conocida como array-CGH se ha establecido como una herramienta diagnóstica de primer orden para el estudio de pacientes con anomalías congénitas, retraso mental no filiado y otras enfermedades neurológicas. Sin embargo, su utilidad como técnica de primer uso en el campo prenatal está actualmente en fase de evaluación, especialmente en embarazos de bajo riesgo. En una población de 530 gestantes con embarazos de bajo riesgo se realizó, simultáneamente, cariotipo convencional y un estudio de array-CGH para el diagnóstico prenatal. Mientras que el cariotipo detectó 3 casos (0,5%) con alteraciones citogéneticas no equilibradas (una de ellas no definida), el array-CGH detectó 8 casos con este tipo de alteraciones (1,5%), identificando el cambio indefinido detectado por cariotipo. Este estudio demuestra positivamente que el array-CGH puede ser una herramienta útil en el diagnóstico prenatal en embarazos de bajo riesgo(AU)

The array-CGH technique has recently been established as a first-tier diagnostic test for studying patients with congenital anomalies, idiopathic mental retardation and other neurological disorders. However, its use in prenatal diagnosis is still being evaluated, especially in low-risk pregnancies. A study was conducted on a population of 530 low-risk pregnancy women using both conventional karyotype and array-CGH for prenatal diagnosis. Whereas conventional karyotype detected 3 foetuses (0.5%) with unbalanced cytogenetic aberrations (one of them was undefined), array-CGH detected 8 foetuses with copy number aberrations (1.5%), and positively identified the undefined cytogenetic aberration detected using karyotype. In conclusion, this study proposes array-CGH as a useful tool in prenatal diagnosis for low-risk pregnancies(AU)

Genotype-phenotype correlation in eight new patients with a deletion encompassing 2q31.1.

Microdeletions of the 2q31.1 region are rare. We present the clinical and molecular findings of eight previously unreported patients with overlapping deletions in 2q31.1. The patients have a variable clinical phenotype and present with developmental delay (7/8), growth retardation (5/8), seizures (2/8) and a craniofacial dysmorphism consisting of microcephaly (4/8), short palpebral fissures (7/8), broad eyebrows with lateral flare (7/8), low-set ears with thickened helices and lobules (5/8), and micrognathia (6/8). Additional congenital anomalies were noted, including limb abnormalities (8/8), heart defects (3/8), genital anomalies (3/8), and craniosynostosis (1/8). Six of these microdeletions, ranging in size from 1.24 to 8.35 Mb, were identified by array CGH, one larger deletion (19.7 Mb) was detected by conventional karyotyping and further characterized by array CGH analysis. The smallest region of overlap in all eight patients spans at most 88 kb and includes only the WIPF1 gene. This gene codes for the WAS/WASL interacting protein family member 1. The patients described here do not present with clinical signs of the Wiskott-Aldrich syndrome and the deletion of this single gene does not allow explaining the phenotype in our patients. It is likely that the deletion of different but overlapping sets of genes from 2q31 is responsible for the clinical variability in these patients. To further dissect the complex phenotype associated with deletions in 2q31, additional patients with overlapping phenotypes should be examined with array CGH. This should help to link particular phenotypes to specific genes, and add to our understanding of the underlying developmental processes.

Molecular study of VWF gene from Mexican Mestizo patients with von Willebrand disease, and the finding of three new mutations.

To investigate the origin of von Willebrand disease in Mexican Mestizo population, we analyzed exons 18, 19, 20, 28, 45, and 52 of the VWF gene from 34 Mexican Mestizo index cases, 28 of them affected but not related, using DNA amplification by polymerase chain reaction and direct sequencing. We found three novel mutations: E1447Q in one patient with type 1; P2781S in one patient with type 2M; and P812L in another type 1/2N patient. These mutations were not found in 100 normal alleles. Moreover, we found other mutations previously reported in the literature; one of them (G1609R) was the most frequent (6/28) in patients with VWD type 2A. This is the first molecular study in a Mexican group that has a particular mixture of Indigenous, Caucasian, and African genes.

Risk of recurrence in patients with surgically resected stage I non-small cell lung carcinoma: histopathologic and immunohistochemical analysis.

STUDY OBJECTIVE: To evaluate the prognostic value of histopathologic variables and molecular markers in a group of patients with stage I non-small cell lung cancer (NSCLC). SETTING: "María Ferrer" Hospital of Buenos Aires, Argentina. PATIENTS: Pathologic stage IA and IB patients who underwent radical surgery and nonneoadjuvant therapy for NSCLC between January 1985 and December 1999. MEASUREMENTS AND RESULTS: Fifty-three patients fulfilling the inclusion criteria were identified. The overall survival was 52.8%, and 28% of patients had recurrent disease. We found significant differences between squamous cell carcinoma (SCC) and adenocarcinoma in mitotic counting (p = 0.001) and lymphatic permeation (p = 0.01). SCCs showed higher proliferation (MIB-1 grades 2 and 3) [p = 0.001], Bcl-2 expression (p = 0.038), and CD44 expression (p = 0.019) than adenocarcinomas. The log-rank test showed that mitosis count, necrosis, MIB-1, and Bcl-2 were predictive factors for relapse. All of them were associated with increased relapse and a shorter time to recurrence. Multivariate analysis using the Cox proportional hazards regression model showed that mitosis count, Bcl-2 expression, and grade 3 of MIB-1 emerged as independent prognostic factors of recurrence. CONCLUSIONS: We found that mitosis count and MIB-1 expression had significant value to predict recurrence, reflecting the aggressiveness of high-rate proliferative tumors. We could also show that patients with positive Bcl-2 tumors had a poor outcome, probably related to the uncontrolled cell growth that the expression of Bcl-2 promotes. Our observations are of potential interest for the development of rational postresection treatment strategies based on the estimated risk of recurrence of patients with NSCLC.

Diagnosis of lupus anticoagulant in the lupus anticoagulant-hypoprothrombinemia syndrome: report of two cases and review of the literature.

We report a severe hemorrhagic disorder in two pediatric patients with lupus anticoagulant (LA) associated to acquired factor II (prothrombin) deficiency. In both patients, hemorrhagic symptoms resolved after corticosteroid therapy. Serial coagulation studies showed that Staclot LA assay was more sensitive than DVVconfirm and Staclot PNP tests to confirm the presence of LA when associated with severe factor II deficiency. Both patients had non-neutralizing anti-prothrombin antibodies and their titers inversely correlated with factor II activity (r = -1.0, P < 0.0001). Associated findings in these patients included positive immunologic tests for systemic lupus erythematosus, a positive anti-cardiolipin antibody, and anti-beta(2) GPI antibodies in one case. Our findings point out the difficulty in diagnosing LA associated with acquired factor II deficiency and suggest that, in confirmation of its phospholipid dependency, the inclusion of a source of normal human plasma in the test sequence to correct for any factor deficiency and a confirmatory step utilizing hexagonal (II) phase phospholipids may be crucial to the diagnosis of LA in some patients with LA-hypoprothrombinemia syndrome.