Hereditary spastic paraplegia in Greece: characterisation of a previously unexplored population using next-generation sequencing

Hereditary Spastic Paraplegia (HSP) is a syndrome characterised by lower limb spasticity, occurring alone or in association with other neurological manifestations, such as cognitive impairment, seizures, ataxia or neuropathy. HSP occurs worldwide, with different populations having different frequencies of causative genes. The Greek population has not yet been characterised. The purpose of this study was to describe the clinical presentation and molecular epidemiology of the largest cohort of HSP in Greece, comprising 54 patients from 40 families. We used a targeted next-generation sequencing (NGS) approach to genetically assess a proband from each family. We made a genetic diagnosis in >50% of cases and identified 11 novel variants. Variants in SPAST and KIF5A were the most common causes of autosomal dominant HSP, whereas SPG11 and CYP7B1 were the most common cause of autosomal recessive HSP. We identified a novel variant in SPG11, which led to disease with later onset and may be unique to the Greek population and report the first nonsense mutation in KIF5A. Interestingly, the frequency of HSP mutations in the Greek population, which is relatively isolated, was very similar to other European populations. We confirm that NGS approaches are an efficient diagnostic tool and should be employed early in the assessment of HSP patients

The FGF14 GAA repeat expansion in Greek patients with late-onset cerebellar ataxia and an overview of the SCA27B phenotype across populations

A pathogenic GAA repeat expansion in the first intron of the fibroblast growth factor 14 gene (FGF14) has been recently identified as the cause of spinocerebellar ataxia 27B (SCA27B). We herein screened 160 Greek index cases with late-onset cerebellar ataxia (LOCA) for FGF14 repeat expansions using a combination of long-range PCR and bidirectional repeat-primed PCRs. We identified 19 index cases (12%) carrying a pathogenic FGF14 GAA expansion, a diagnostic yield higher than that of previously screened repeat-expansion ataxias in Greek LOCA patients. The age at onset of SCA27B patients was 60.5 ± 12.3 years (range, 34–80). Episodic onset (37%), downbeat nystagmus (32%) and vertigo (26%) were significantly more frequent in FGF14 expansion-positive cases compared to expansion-negative cases. Beyond typical cerebellar signs, SCA27B patients often displayed hyperreflexia (47%) and reduced vibration sense in the lower extremities (42%). The frequency and phenotypic profile of SCA27B in Greek patients was similar to most other previously studied populations. We conclude that FGF14 GAA repeat expansions are the commonest known genetic cause of LOCA in the Greek population and recommend prioritizing testing for FGF14 expansions in the diagnostic algorithm of patients with LOCA

Spastic paraplegia preceding PSEN1-related familial Alzheimer's disease.

Introduction: We investigated the frequency, neuropathology, and phenotypic characteristics of spastic paraplegia (SP) that precedes dementia in presenilin 1 (PSEN1) related familial Alzheimer's disease (AD). Methods: We performed whole exome sequencing (WES) in 60 probands with hereditary spastic paraplegia (HSP) phenotype that was negative for variants in known HSP-related genes. Where PSEN1 mutation was identified, brain biopsy was performed. We investigated the link between HSP and AD with PSEN1 in silico pathway analysis and measured in vivo the stability of PSEN1 mutant γ-secretase. Results: We identified a PSEN1 variant (p.Thr291Pro) in an individual presenting with pure SP at 30 years of age. Three years later, SP was associated with severe, fast cognitive decline and amyloid deposition with diffuse cortical plaques on brain biopsy. Biochemical analysis of p.Thr291Pro PSEN1 revealed that although the mutation does not alter active γ-secretase reconstitution, it destabilizes γ-secretase-amyloid precursor protein (APP)/amyloid beta (Aβn) interactions during proteolysis, enhancing the production of longer Aβ peptides. We then extended our analysis to all 226 PSEN1 pathogenic variants reported and show that 7.5% were associated with pure SP onset followed by cognitive decline later in the disease. We found that PSEN1 cases manifesting initially as SP have a later age of onset, are associated with mutations located beyond codon 200, and showed larger diffuse, cored plaques, amyloid-ring arteries, and severe CAA. Discussion: We show that pure SP can precede dementia onset in PSEN1-related familial AD. We recommend PSEN1 genetic testing in patients presenting with SP with no variants in known HSP-related genes, particularly when associated with a family history of cognitive decline

Mosaicism for combined tetrasomy of chromosomes 8 and 18 in a dysmorphic child: A result of failed tetraploidy correction?

<p>Abstract</p> <p>Background</p> <p>Mosaic whole-chromosome tetrasomy has not previously been described as a cause of fetal malformations.</p> <p>Case presentation</p> <p>In a markedly dysmorphic child with heart malformations and developmental delay, CGH analysis of newborn blood DNA suggested a 50% dose increase of chromosomes 8 and 18, despite a normal standard karyotype investigation. Subsequent FISH analysis revealed leukocytes with four chromosomes 8 and four chromosomes 18. The child's phenotype had resemblance to both mosaic trisomy 8 and mosaic trisomy 18. The double tetrasomy was caused by mitotic malsegregation of all four chromatids of both chromosome pairs. A possible origin of such an error is incomplete correction of a tetraploid state resulting from failed cytokinesis or mitotic slippage during early embryonic development.</p> <p>Conclusion</p> <p>This unique case suggests that embryonic cells may have a mechanism for tetraploidy correction that involves mitotic pairing of homologous chromosomes.</p

Genetic screening of Greek patients with Huntington&apos;s disease phenocopies identifies an SCA8 expansion

Huntington’s disease (HD) is an autosomal dominant disorder characterized by a triad of chorea, psychiatric disturbance and cognitive decline. Around 1% of patients with HD-like symptoms lack the causative HD expansion and are considered HD phenocopies. Genetic diseases that can present as HD phenocopies include HD-like syndromes such as HDL1, HDL2 and HDL4 (SCA17), some spinocerebellar ataxias (SCAs) and dentatorubral-pallidoluysian atrophy (DRPLA). In this study we screened a cohort of 21 Greek patients with HD phenocopy syndromes for mutations causing HDL2, SCA17, SCA1, SCA2, SCA3, SCA8, SCA12 and DRPLA. Fifteen patients (71%) had a positive family history. We identified one patient (4.8% of the total cohort) with an expansion of 81 combined CTA/CTG repeats at the SCA8 locus. This falls within what is believed to be the high-penetrance allele range. In addition to the classic HD triad, the patient had features of dystonia and oculomotor apraxia. There were no cases of HDL2, SCA17, SCA1, SCA2, SCA3, SCA12 or DRPLA. Given the controversy surrounding the SCA8 expansion, the present finding may be incidental. However, if pathogenic, it broadens the phenotype that may be associated with SCA8 expansions. The absence of any other mutations in our cohort is not surprising, given the low probability of reaching a genetic diagnosis in HD phenocopy patients

Two different schedules of irinotecan (CPT-11) in patients with advanced colorectal carcinoma relapsing after a 5-fluorouracil and leucovorin combination. A randomized study

Purpose. To evaluate the efficacy and safety of irinotecan as second-line treatment in patients with advanced colorectal cancer (ACC) failing or relapsing after 5-fluorouracil (5-FU) plus leucovorin (LV) standard chemotherapy. &lt;LF&gt;Patients and methods. Irinotecan was randomly administered in two different schedules (once every 3 weeks, and every 10 days) in patients failing prior 5-FU plus LV. Patients were randomized to two treatment groups: group A received irinotecan 350 mg/m(2) every 21 days and group B received irinotecan 175 mg/m(2) days 1 and 10 every 21 days. Results. Group A comprised 60 patients: 34 male/26 female, median age 64 years (range 48-70 years), and median Karnofsky performance status (PS) 90. Their metastatic sites included liver (n=47), lymph nodes (n=27), lung (n=14), abdomen (n=14), pelvis (n=8), ‘other’ (n=2), and local recurrence (n=12). Group B comprised 60 patients: 36 male/24 female, median age 62 years (46-70 years), and median PS 90. Their metastatic sites included liver (n=49), lymph nodes (n=29), lung (n=17), abdomen (n=16), pelvis (n=11), ‘other’ (n=2), and local recurrence (n=13). Group A showed the following responses: complete response (CR) 2, partial response (PR) 12, stable disease (SD) 21, progressive disease (PD) 26, overall response rate (ORR) 23%, tumor growth control 58%. Group B showed the following responses: CR 1, PR 14, SD 22, PD 23; ORR 25%; tumor growth control 62%. Toxicities included acute cholinergic syndrome (group A 53%, group B 19%; P&lt;0.0001), late-onset diarrhea grade 1/2 (group A 21%, group B 46%) and grade 3/4 (group A 41%, group B 66%; P&lt;0.0001), nausea and vomiting grade 1/2 (group A 34%, group B 59%) and grade 3/4 (group A 30%, group B 12%; P&lt;0.0001), neutropenia grade 3/4 (group A 27%, group B 28%; P&lt;0.03), with febrile neutropenia seen in only four patients in group A, anemia grade more than 2 (group A 28%, group B 12%; P&lt;0.05), asthenia grade more than 3 (group A 24%, group B 18%; P&lt;0.001), and alopecia grade more than 3 (group A 40%, group B 34%; P&lt;0.2). Conclusions. The present study indicates that, in patients with ACC who have relapsed after 5-FU plus LV, the administration of irinotecan fractionated into two doses every 21 days yields a similar efficacy to, but a much lower incidence of toxicity than, the same total dose of irinotecan administered once every 21 days

Efficacy of tropisetron in patients with advanced non-small-cell lung cancer receiving adjuvant chemotherapy with carboplatin and taxanes

Even though significant progress has been made, chemotherapy-induced emesis remains a challenging problem. Few studies focus on emesis in patients treated with carboplatin and the observation period is limited to the initial 24 h following chemotherapy. Thus, we investigated if tropisetron (T) monotherapy can adequately prevent acute and delayed emesis in non-small-cell lung cancer (NSCLC) patients receiving a moderately emetogenic chemotherapy (MEC) (carboplatin-containing) regimen. Furthermore, we explored the merits of adding dexamethasone (D) or alprazolam (A) to T, especially in the setting of a pre-existing high level of stress. We studied 60 patients with advanced NSCLC receiving carboplatin and taxanes in three consecutive cycles. During the first cycle, patients received 5 mg of T intravenously before chemotherapy and the same dose per os on each of the following 3 days. In the second cycle, T was co-administered with 8 mg of D once a day, while, during the third cycle, T was combined with per os A 0.25 mg every 12 h and continued over the following 3 days. Finally, we evaluated the impact of stress on the anti-emetic response achieved with the previously described regimens. The combination of T + A was superior to T monotherapy and the combination of T + D, regarding the prevention of acute and delayed emesis. Both T + A and T + D combinations led to appetite improvement, while patients receiving T + A experienced sedation more frequently. Interestingly, subgroup analysis revealed that patients without underlying stress obtained no further benefit by the addition of A or D, while both T + A and T + D combinations led to a better anti-emetic response in patients with stress. In conclusion, T monotherapy provides a satisfactory result in controlling nausea and emesis caused by a MEC regimen in patients without stress. However, the addition of D and, mainly, A improves its anti-emetic effect in patients with obvious stress. © 2007 Blackwell Publishing Ltd