Experience of a 2-year spinal muscular atrophy NBS pilot study in Italy: towards specific guidelines and standard operating procedures for the molecular diagnosis.

BACKGROUND: Spinal muscular atrophy (SMA) is due to the homozygous absence of SMN1 in around 97% of patients, independent of the severity (classically ranked into types I-III). The high genetic homogeneity, coupled with the excellent results of presymptomatic treatments of patients with each of the three disease-modifying therapies available, makes SMA one of the golden candidates to genetic newborn screening (NBS) (SMA-NBS). The implementation of SMA in NBS national programmes occurring in some countries is an arising new issue that the scientific community has to address. We report here the results of the first Italian SMA-NBS project and provide some proposals for updating the current molecular diagnostic scenario. METHODS: The screening test was performed by an in-house-developed qPCR assay, amplifying SMN1 and SMN2. Molecular prognosis was assessed on fresh blood samples. RESULTS: We found 15 patients/90885 newborns (incidence 1:6059) having the following SMN2 genotypes: 1 (one patient), 2 (eight patients), 2+c.859G>C variant (one patient), 3 (three patients), 4 (one patient) or 6 copies (one patient). Six patients (40%) showed signs suggestive of SMA at birth. We also discuss some unusual cases we found. CONCLUSION: The molecular diagnosis of SMA needs to adapt to the new era of the disease with specific guidelines and standard operating procedures. In detail, SMA diagnosis should be felt as a true medical urgency due to therapeutic implications; SMN2 copy assessment needs to be standardised; commercially available tests need to be improved for higher SMN2 copies determination; and the SMN2 splicing-modifier variants should be routinely tested in SMA-NBS.

SMA-miRs (miR-181a-5p, -324-5p, and -451a) are overexpressed in spinal muscular atrophy skeletal muscle and serum samples.

Background: Spinal muscular atrophy (SMA) is a neuromuscular disorder characterized by the degeneration of the second motor neuron. The phenotype ranges from very severe to very mild forms. All patients have the homozygous loss of the SMN1 gene and a variable number of SMN2 (generally 2-4 copies), inversely related to the severity. The amazing results of the available treatments have made compelling the need of prognostic biomarkers to predict the progression trajectories of patients. Besides the SMN2 products, few other biomarkers have been evaluated so far, including some miRs. Methods: We performed whole miRNome analysis of muscle samples of patients and controls (14 biopsies and 9 cultures). The levels of muscle differentially expressed miRs were evaluated in serum samples (51 patients and 37 controls) and integrated with SMN2 copies, SMN2 full-length transcript levels in blood and age (SMA-score). Results: Over 100 miRs were differentially expressed in SMA muscle; 3 of them (hsa-miR-181a-5p, -324-5p, -451a; SMA-miRs) were significantly upregulated in the serum of patients. The severity predicted by the SMA-score was related to that of the clinical classification at a correlation coefficient of 0.87 (p<10-5). Conclusions: miRNome analyses suggest the primary involvement of skeletal muscle in SMA pathogenesis. The SMA-miRs are likely actively released in the blood flow; their function and target cells require to be elucidated. The accuracy of the SMA-score needs to be verified in replicative studies: if confirmed, its use could be crucial for the routine prognostic assessment, also in presymptomatic patients. Funding: Telethon Italia (grant #GGP12116).

Chromosome 14 deletions, rings, and epilepsy genes: A riddle wrapped in a mystery inside an enigma.

The ring 14 syndrome is a rare condition caused by the rearrangement of one chromosome 14 into a ring-like structure. The formation of the ring requires two breakpoints and loss of material from the short and long arms of the chromosome. Like many other chromosome syndromes, it is characterized by multiple congenital anomalies and developmental delays. Typical of the condition are retinal anomalies and drug-resistant epilepsy. These latter manifestations are not found in individuals who are carriers of comparable 14q deletions without formation of a ring (linear deletions). To find an explanation for this apparent discrepancy and gain insight into the mechanisms leading to seizures, we reviewed and compared literature cases of both ring and linear deletion syndrome with respect to both their clinical manifestations and the role and function of potentially epileptogenic genes. Knowledge of the epilepsy-related genes in chromosome 14 is an important premise for the search of new and effective drugs to combat seizures. Current clinical and molecular evidence is not sufficient to explain the known discrepancies between ring and linear deletions.

Deregulated expression of the imprinted DLK1-DIO3 region in glioblastoma stemlike cells: tumor suppressor role of lncRNA MEG3.

BACKGROUND: Glioblastoma (GBM) stemlike cells (GSCs) are thought to be responsible for the maintenance and aggressiveness of GBM, the most common primary brain tumor in adults. This study aims at elucidating the involvement of deregulations within the imprinted delta-like homolog 1 gene‒type III iodothyronine deiodinase gene (DLK-DIO3) region on chromosome 14q32 in GBM pathogenesis. METHODS: Real-time PCR analyses were performed on GSCs and GBM tissues. Methylation analyses, gene expression, and reverse-phase protein array profiles were used to investigate the tumor suppressor function of the maternally expressed 3 gene (MEG3). RESULTS: Loss of expression of genes and noncoding RNAs within the DLK1-DIO3 region was observed in GSCs and GBM tissues compared with normal brain. This downregulation is mainly mediated by epigenetic silencing. Kaplan-Meier analysis indicated that low expression of MEG3 and MEG8 long noncoding (lnc)RNAs significantly correlated with short survival in GBM patients. MEG3 restoration impairs tumorigenic abilities of GSCs in vitro by inhibiting cell growth, migration, and colony formation and decreases in vivo tumor growth, reducing infiltrative growth. These effects were associated with modulation of genes involved in cell adhesion and epithelial-to-mesenchymal transition (EMT). CONCLUSION: In GBM, MEG3 acts as a tumor suppressor mainly regulating cell adhesion, EMT, and cell proliferation, thus providing a potential candidate for novel GBM therapies.

Allogeneic umbilical cord blood red cell concentrates: an innovative blood product for transfusion therapy of preterm infants.

BACKGROUND: Preterm infants often receive blood transfusions early in life. In this setting, umbilical cord blood (UCB) might be safer than adult blood (A) with respect to infectious and immunologic threats. OBJECTIVES: To evaluate, as a first objective, the feasibility of fulfilling transfusion needs of preterm infants with allogeneic UCB red blood cell (RBC) concentrates and, as a secondary objective, to assess the safety of allogeneic cord blood transfusions. METHODS: At the Neonatal Intensive Care Unit and the UNICATT Cord Blood Bank of 'A. Gemelli' Hospital in Rome, a prospective study was carried out over a 1-year period, enrolling newborns with gestational age ≤30 weeks and/or birth weight ≤1,500 g requiring RBC transfusions within the first 28 days of life. At first transfusion, patients were assigned to receive UCB-RBCs or A-RBCs depending on the availability of ABO-Rh(D)-matched UCB-RBC units. The same regimen (UCB-RBC or A-RBC units) was thereafter maintained, unless ABO-Rh(D)-matched UCB-RBC units were not available. RESULTS: Overall, 23 UCB-RBC units were transfused to 9 patients; the requests for UCB-RBC units were met in 45% of patients at the first transfusion and in 78% at the subsequent transfusions. At a median follow-up of 57 days (range 6-219), no acute or delayed transfusion-related adverse events occurred. Hematocrit gain after transfusion and time intervals between transfusions were similar in the UCB-RBC and A-RBC group, as well. CONCLUSIONS: Transfusing allogeneic UCB-RBC units in preterm infants appears a feasible and safe approach, although the transfusion needs of our study population were not completely covered. More data are necessary to validate this novel transfusion practice.

Acute lung injury complicating blood transfusion in post-partum hemorrhage: incidence and risk factors.

BACKGROUND: We retrospectively investigated the incidence and risk factors for transfusion-related acute lung injury (TRALI) among patients transfused for post-partum hemorrhage (PPH). METHODS: We identified a series of 71 consecutive patients with PPH requiring the urgent transfusion of three or more red blood cell (RBC) units, with or without transfusion of fresh frozen plasma (FFP) and/or platelets (PLT). Clinical records were then retrieved and examined for respiratory distress events. According to the 2004 consensus definition, cases of new-onset hypoxemia, within 6 hours after transfusion, with bilateral pulmonary changes, in the absence of cardiogenic pulmonary edema were identified as TRALI. If an alternative risk factor for acute lung injury was present, possible TRALI was diagnosed. RESULTS: Thirteen cases of TRALI and 1 case of possible TRALI were identified (overall incidence 19.7%). At univariate analysis, patients with TRALI received higher number of RBC, PLT and FFP units and had a longer postpartum hospitalization. Among the diseases occurring in pregnancy- and various pre-existing comorbidities, only gestational hypertension and pre-eclampsia, significantly increased the risk to develop TRALI (p = 0.006). At multivariate analysis including both transfusion- and patient-related risk factors, pregnancy-related, hypertensive disorders were confirmed to be the only predictors for TRALI, with an odds ratio of 27.7 ( 95% CI 1.27-604.3, p=0.034). CONCLUSIONS: Patients suffering from PPH represent a high-risk population for TRALI. The patients with gestational hypertension and pre-eclampsia, not receiving anti-hypertensive therapy, have the highest risk. Therefore, a careful monitoring of these patients after transfusions is recommended.