Ilka Warshawsky

Detection of a novel point mutation of the prothrombin gene at position 20209.

Detection of the prothrombin G20210A mutation was performed on the LightCycler Instrument (Roche Molecular Biochemicals, Mannheim, Germany) using commercially available primers and hybridization probes. Herein we report four cases from unrelated African American individuals where LightCycler analysis showed atypical melting curves. Sequence analysis of the four samples showed heterozygosity for a C to T mutation 1 bp upstream from the known 20210 mutation at position 20209. The clinical significance of this mutation is not known, but three patients in whom it was detected had a history of venous thrombosis or stroke. The fourth patient had severe liver disease, which may have masked thrombotic predisposition. Since most assays used to detect the G20210A mutation use a PCR/restriction digestion assay, which would not detect the C20209T mutation, this new mutation may be underrecognized when prothrombin gene mutation testing is performed by PCR/restriction digestion assay.

Primary progressive multiple sclerosis as a phenotype of a PLP1 gene mutation.

We report a 49‐year‐old woman with a history of progressive gait disturbance, white matter disease, and cerebrospinal fluid immunoglobulin abnormalities who met criteria for primary progressive multiple sclerosis and whose son died at age 10 years of an unknown congenital neurodevelopmental disorder. Sequencing of the proteolipid protein 1 gene showed a novel mutation, Leu30Arg (c.89T〉G), in the mother and son. Pelizaeus–Merzbacher disease is the cause of death in the son and explains the mothers adult‐onset neurological disorder. This case goes against dogma that mothers of severely affected sons are asymptomatic as adults and expands the differential diagnosis of primary progressive multiple sclerosis to include proteolipid protein 1 gene mutations. Ann Neurol 2005;58:470–473

Comparison of five methods for extraction of Legionella pneumophila from respiratory specimens.

ABSTRACT The efficiencies of five commercially available nucleic acid extraction methods were evaluated for the recovery of a standardized inoculum of Legionella pneumophila in respiratory specimens (sputum and bronchoalveolar lavage [BAL] specimens). The concentrations of Legionella DNA recovered from sputa with the automated MagNA Pure (526,200 CFU/ml) and NucliSens (171,800 CFU/ml) extractors were greater than those recovered with the manual methods (i.e., Roche High Pure kit [133,900 CFU/ml], QIAamp DNA Mini kit [46,380 CFU/ml], and ViralXpress kit [13,635 CFU/ml]). The rank order was the same for extracts from BAL specimens, except that for this specimen type the QIAamp DNA Mini kit recovered more than the Roche High Pure kit.

Primary adenocarcinoma in a donor lung: evaluation and surgical management

We report a case of primary non-small cell cancer diagnosed in the donor lung 33 months after bilateral pulmonary transplantation. The tumor was treated surgically. A lingular sparing left upper lobe bisegmental lung resection was performed.

A comparison of multiplex and monoplex T-cell receptor gamma PCR.

T-cell receptor gamma (TCRγ) PCR is often used to detect clonal T-cell populations. Because TCRγ contains a limited number of variable (Vγ) and joining (Jγ) regions, a small number of PCR primers can be used to assess T-cell clonality. The seven primers used in the current study were described previously and were split into 2 or 3 multiplex primer sets. In this study, a single 7-primer multiplex (7-plex) PCR reaction was compared with all 12 possible monoplex primer combinations on 18 samples previously analyzed for T-cell receptor rearrangements by TCRβ Southern blot and/or TCRγ PCR followed by temporal temperature gradient gel electrophoresis. Using fluorescent Vγ-region primers, unlabeled Jγ-region primers, and capillary electrophoresis, we show all TCRγ rearrangements seen by 7-plex PCR on known positive samples were seen following monoplex PCR. However, additional TCRγ gene rearrangements were seen in monoplex PCR reactions that were not seen in the 7-plex PCR reactions. Monoplex but not 7-plex PCR of known negative samples occasionally showed TCRγgene rearrangements, often with less frequently used Vγ and Jγ-region primers, and may have represented false positive results. In summary, the single 7-plex PCR reaction correctly identified specimens with TCRγ clonal populations and represents an improvement over existing assays that use these same primers split into several smaller multiplex reactions. Monoplex PCR has no advantage over multiplex PCR and has the potential to lead to false positive results.