Clinical and mutational spectrum of Charcot-Marie-Tooth disease type 2Z caused by MORC2 variants in Japan

BACKGROUND AND PURPOSE

The microrchidia family CW-type zinc finger 2 gene (MORC2) was newly identified as a causative gene of Charcot-Marie-Tooth disease (CMT) type 2Z in 2016. We aimed to describe the clinical and mutational spectrum of patients with CMT harboring MORC2 mutations in Japan.

METHODS

We analyzed samples from 781 unrelated patients clinically diagnosed with CMT using deoxyribonucleic acid microarray or targeted resequencing by next-generation sequencing, and samples from 434 mutation-negative patients were subjected to whole-exome sequencing. We extracted MORC2 variants from these whole-exome sequencing data and classified them according to American College of Medical Genetics standards and guidelines.

RESULTS

We identified MORC2 variants in 13 patients. As the second most common causative gene of CMT type 2 after MFN2, MORC2 variants were detected in 2.7% of patients with CMT type 2. The mean age of onset was 10.3 ± 8.7 years, and the inheritance pattern was mostly sporadic (11/13 patients, 84.6%). The clinical phenotype was typically length-dependent polyneuropathy, and electrophysiological studies revealed sensory-dominant axonal neuropathy. Mental retardation was identified in 4/13 patients (30.8%). p.Arg190Trp, as a mutational hotspot, was observed in eight unrelated families. We also identified two novel probably pathogenic variants, p.Cys345Tyr and p.Ala369Val, and one novel uncertain significance variant, p.Tyr332Cys.

CONCLUSIONS

Our study is the largest report of patients harboring MORC2 variants. We revealed a clinical and mutational spectrum of Japanese patients with MORC2 variants. More attention should be paid to cognitive impairment, and the responsible mechanism requires further research for elucidation.

Clinical and mutational spectrum of Japanese patients with Charcot-Marie-Tooth disease caused by GDAP1 variants

BACKGROUND

Mutations in GDAP1 are responsible for heterogeneous clinical and electrophysiological phenotypes of Charcot-Marie-Tooth disease (CMT), with autosomal dominant or recessive inheritance pattern. The aim of this study is to identify the clinical and mutational spectrum of CMT patients with GDAP1 variants in Japan.

MATERIALS AND METHODS

From April 2007 to October 2014, using three state-of-art technologies, we conducted gene panel sequencing in a cohort of 1,030 patients with inherited peripheral neuropathies (IPNs), and 398 mutation-negative cases were further analyzed with whole-exome sequencing.

RESULTS

We identified GDAP1 variants from 10 patients clinically diagnosed with CMT. The most frequent recessive variant in our cohort (5/10), c.740C>T (p.A247V), was verified to be associated with a founder event. We also detected three novel likely pathogenic variants: c.928C>T (p.R310W) and c.546delA (p.E183Kfs*23) in Case 2 and c.376G>A (p.E126K) in Case 8. Nerve conduction study or sural nerve biopsy of all 10 patients indicated axonal type peripheral neuropathy.

CONCLUSION

We identified GDAP1 variants in approximately 1% of our cohort with IPNs, and established a founder mutation in half of these patients. Our study originally described the mutational spectrum and clinical features of GDAP1-related CMT patients in Japan.

Successful management of complete placenta previa after intrauterine fetal death in a second-trimester pregnancy by uterine artery embolization: case report and literature review

A 27-year-old woman with complete placenta previa was referred at 22 weeks of gestation because of vaginal bleeding and fetal growth restriction. At 24 weeks, sudden fetal death occurred, but bleeding continued and transvaginal sonography revealed abundant periplacental blood flow in the uterine wall. To avoid cesarean section, the authors performed uterine artery embolization (UAE) be- fore vaginal delivery of the fetus. Subsequently, there was little bleeding when laminaria was inserted for cervical ripening and the fetus was delivered vaginally by using vaginal gemeprost. Total blood loss was only 149 ml. The present case suggests that UAE may be an option for patients with placenta previa who desire vaginal delivery after intrauterine fetal death (IUFD) in a second-trimester pregnancy.

Pericardiectomy and pericardium window creation to treat recurrent pericardial tamponade involving a borderline ovarian tumor

PURPOSE OF INVESTIGATION

Pericardial effusion with cardiac tamponade is an uncommon metastatic manifestation of ovarian tumors, with only one previously reported case involving a borderline ovarian tumor (BOT).

CASE

A 50-year-old woman was diagnosed and treated for a primary Stage IIc BOT. The disease recurred as an emergency pericardiocentesis eight years later, which was resected following pericardial effusion with a cardiac tamponade. This occurred two more times, and on the last occasion, drainage failed to relieve her symptoms. However, her symptoms resolved after the creation of a pericardium pleural window together with a pericardiectomy.

CONCLUSION

For patients with a metastatic BOT, the creation of a pericardium pleural window and pericardiectomy is effective for recurrent pericardial tamponade, if the pericardial space is posteriorly located and/or segmented.

Effects of bisphosphonates on human esophageal squamous cell carcinoma cell survival

Esophageal squamous cell carcinoma (ESCC) is one of the most malignant cancers in Japan. Anticancer chemotherapy has been useful for ESCC treatment. However, therapeutic options are limited. Recently, bisphosphonates (BPs), which are osteoporosis drugs, have shown anticancer effects in several cancer cell lines, but the effects against ESCC cell lines are unknown. In this study, we examined the cytotoxic effects of BPs and their mechanisms of cytotoxicity in human ESCC cell lines. A first-generation BP (etidronate), two second-generation BPs (alendronate and pamidronate), and two third-generation BPs (risedronate and zoledronate) were used in this study. All BPs, except etidronate, were cytotoxic, as indicated by increased caspase-3/7 activity and numbers of Annexin-fluorescein isothiocyanate positive cells in ESCC cell lines. From cell cycle analysis, G0/G1-phase arrest was observed upon treatment with second- and third-generation BPs. In addition, Cyclin D1 protein expression levels were decreased by second- and third-generation BP treatment. Although squalene and trans, trans-farnesol minimally affected BP cytotoxicity, treatment with geranylgeraniol inhibited BP cytotoxicity almost completely. We concluded that second- and third-generation BPs are cytotoxic to ESCC cell lines as they induce apoptosis and inhibit the cell cycle through mevalonate pathway inhibition. Therefore, BP treatment may be a beneficial therapy in ESCC patients.

Monocyte CD64 expression as a novel biomarker for the disease activity of systemic lupus erythematosus

Objective

Interferon alpha (IFN-α) is a key cytokine associated with systemic lupus erythematosus (SLE). IFN-α induces the expression of CD64 on monocytes (mCD64). Although enhanced mCD64 expression has been reported in patients with SLE, it has never been assessed quantitatively. The aim of this study was to investigate whether or not mCD64 expression correlates with SLE disease activity.

Methods

The mCD64 expression levels were assessed quantitatively in 40 patients with active or inactive SLE by using flow cytometry. The mCD64 expression levels were subsequently compared with the SLE disease activity index (SLEDAI) and levels of existing SLE activity biomarkers, such as anti-DNA antibody, complements, and so on.

Results

The mCD64 expression was significantly higher in active disease than in inactive disease SLE (median molecules/cell, interquartile range: 34,648, 8174–24,932 and 20,865, 6357–21,503, respectively; p < 0.001). The levels of mCD64 expression strongly correlated with SLEDAI ( r = 0.68, p < 0.001).

Conclusion

The mCD64 expression is a simple and useful biomarker for evaluating disease activity in patients with SLE.

Usefulness of quantitative susceptibility mapping for the diagnosis of Parkinson disease

BACKGROUND AND PURPOSE

Quantitative susceptibility mapping allows overcoming several nonlocal restrictions of susceptibility-weighted and phase imaging and enables quantification of magnetic susceptibility. We compared the diagnostic accuracy of quantitative susceptibility mapping and R2* (1/T2*) mapping to discriminate between patients with Parkinson disease and controls.

MATERIALS AND METHODS

For 21 patients with Parkinson disease and 21 age- and sex-matched controls, 2 radiologists measured the quantitative susceptibility mapping values and R2* values in 6 brain structures (the thalamus, putamen, caudate nucleus, pallidum, substantia nigra, and red nucleus).

RESULTS

The quantitative susceptibility mapping values and R2* values of the substantia nigra were significantly higher in patients with Parkinson disease (P < .01); measurements in other brain regions did not differ significantly between patients and controls. For the discrimination of patients with Parkinson disease from controls, receiver operating characteristic analysis suggested that the optimal cutoff values for the substantia nigra, based on the Youden Index, were >0.210 for quantitative susceptibility mapping and >28.8 for R2*. The sensitivity, specificity, and accuracy of quantitative susceptibility mapping were 90% (19 of 21), 86% (18 of 21), and 88% (37 of 42), respectively; for R2* mapping, they were 81% (17 of 21), 52% (11 of 21), and 67% (28 of 42). Pair-wise comparisons showed that the areas under the receiver operating characteristic curves were significantly larger for quantitative susceptibility mapping than for R2* mapping (0.91 versus 0.69, P < .05).

CONCLUSIONS

Quantitative susceptibility mapping showed higher diagnostic performance than R2* mapping for the discrimination between patients with Parkinson disease and controls.