[Hepatoblastoma, Etiology, Case Reports]

Hepatoblastoma is an uncommon malignant neoplasm in general, yet, it is the most common liver malignancy in children with the incidence about one per milion children. This type of liver tumor usually occurs before the age of three years. The etiology of hepatoblastoma remains unknown. However, there are some genetic conditions known to be associated with an increased risk of developing hepatoblastoma such as Beckwith-Wiedemann syndrome, hemihypertrophy, APC-associated polyposis, α-1-antitrypsin defficiency and some metabolic disorders including tyrosinemia, galactosemia and glycogen storage disease type 1. There is a higher risk of hepatoblastoma in children with very low birthweight, children who acquire hepatitis B at an early age and children with congenital biliary atresia.

[Hemoglobin Sydney--alpha beta 2 67 (E11) Val-Ala and hemoglobin Olomouc alpha 2 beta 2 86 (F 2) Ala-Asp in Czech families. DNA sequence analysis for a more accurate diagnosis of hemoglobinopathies]

The paper demonstrates the importance of sequence analysis of DNA for the identification of Hb-Sydney [alpha2-beta2 67 (E11) Val-Ala]. The latter was considered erroneously, based on results of biochemical analyses to be Hb-M-Milwaukee [alpha2 beta2 67 (E 11) Val-Glu]. With the unstable Hb-Sydney correspond also phenotypical manifestations of disease (haemolytic anaemia with Heinz bodies in red blood cells). Sequence analysis of DNA of patients with Hb-Olomouc [alpha 2 beta 2 (F 2) Ala-Asp] revealed that mutation of Ala-Asp in position 86 (F 2) of the beta globin chain is coded by mutation C-->A (GCC-GAC).

[Molecular-genetic characteristics of alpha, beta and delta beta-thalassemias in 139 heterozygotes in 56 unrelated Czech and Slovak families (Priority description of 3 beta-thalassemia mutations, an extensive alpha-thalassemia 2 (18+ kb) deletion and a Swiss-type nondeletion hereditary persistence of hemoglobin F)]

In 135 subjects from 54 unrelated families of Czech and Slovak families the authors identified 11 different beta-thalassaemic alleles. In 25 families they proved a IVS I-1 (G-A) mutation. Another 4 "mediterranean" mutations: IVS II-1 (G-A), IVS II-745 (C-G); IVS I-110 (G-A) and mutations in the codon 39 (C-T) were found in 18 families. Mutation IVS I-5 (G-C) found in one family is common in Asia. A frameshift at codons 82/83(-G) found in two families, was described previously only by Schwartz in one families from Azerbaijan. A rare mutation in codon 121 (C-T) is usually characterized as beta-thal. with formation of Heinz bodies. The latter were however found only in one of three families with this allele. Newly detected alleles include: mutation in codon 112 (T-A) found in one family (surprisingly also without formation of Heinz bodies); mutation in CD 115 (GCC-GAC) which results in unstable variant of Hb-Hradec Králové alpha 2 beta 2 115 (G17) Ala-Asp with formation of Heinz bodies and a frame shift in codons 38/39(-C) found in two families. In one of them there was also a new mutation of the promotor area of the G gamma gene (-110 A-C) causing the Swiss type of the disease with hereditary persistence F haemoglobin. The so-called Sicilian type of delta beta thalassaemia caused by deletion of DNA length cca 13 kb starting in IVS-II was found in one patient. alpha-thalassaemic mutations are rare in this population. In addition to common alpha-thalassaemia 2(-3,7 kb) deletion, however, also a new alpha-thalassaemia 2 was found caused by a large (18+kb) deletion involving alpha 1 and theta globin genes. alpha alpha alpha anti 3,7 triplication found in 7 beta-thal. heterozygotes led to deterioration of parameters of the red cell haemogram.

[Dominant beta-thalassemia alleles in the Czech and Slovak population (beta-thalassemia mutations in 112(T-A) and 121(G-T) codons and the unstable Hradec Králové hemoglobin or alpha 2 beta 2 115 (G17) Ala-Asp)]

In four unrelated families of Czech and Slovak origin two nonsense dominant beta-thalassaemic alleles (CD 121 (G-T); CD 112 (T-A)) and in one family simple substitution in codon 115 (GCC-GAC) or alpha 2 beta 2 115 (G17) Ala-Asp HB-Hradec Králové were identified. Mutations in codons 112 and 115 were described for the first time. Phenotypic manifestation of beta-thal. intermedia was revealed in three families with CD 121 (G-T) and in a family with a mutation in CD 112, but the phenotypic manifestations differed markedly in individual subjects. Heinz bodies were detected in erythrocytes of the peripheral blood in two families. An exact explanation of phenotypic deviations in patients with the same mutation even within the same family were not obtained even in studies of alpha genes and the promoter area of the beta gene. The unstable variant of Hb-Hradec Králové is manifested in the mother and daughter by haemolytic anaemia with some traits of beta-thal. The authors discuss contemporary findings from the pathophysiology of recessive and dominant beta-thal. mutations and explain some of the phenotypic consequences. A relatively high incidence of dominant beta-thal. mutations in the Czech and Slovak Republic (4 of 12 families known world wide with a nonsense beta-thal. mutation in the 3rd exon) is explained by the absence of selective preference of these mutations in malaria infested areas as a result of serious clinical manifestations in heterozygotes. The haplotype in one of the families suggests a de novo origin of the mutation in CD 121.

[Haplotypes of the beta-globulin locus in Czechs and Slovaks with beta-thalassemia and structurally variant hemoglobins]

In 29 Czech and Slovak families with the most frequent and newly identified beta-thalassaemic alleles and with some structural haemoglobin variants (Hb E, Hb Haná, Hb Santa Ana) haplotypes of the beta-globin locus of alleles with these mutations were identified. In most instances haplotypes I and V were involved which were found in 57% of the patients. The bond of the most common beta-thalassaemic mutation: IVS-I-1, IVS-I-110, CD 39 (C-T), IVS-II-745, IVS-I-6 with alleles with the same haplotypes as in the mediterranean region suggests a mediterranean origin of these mutations. In Hb Santa Ana a hitherto not described haplotype was identified (-(+)-(-)-(+3), indicating a de novo origin of the mutation. Also in newly identified beta-thalassaemic mutations in CD 7/8 (+G), in CD 38/39 (-C) and in HbE and Hb Haná de novo development is probable.

The First Pediatric Case of an IFT140 Heterozygous Deletion Causing Autosomal Dominant Polycystic Kidney Disease: Case Report

Introduction

Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disease, which is mainly caused by pathogenic variants in two particular genes: PKD1 and PKD2. ADPKD caused by variants in other genes (GANAB or IFT140) is very rare.

Case Report

In a 6-year-old girl examined for abdominal pain, a cystic mass in the upper part of the right kidney was detected during an abdominal ultrasound. She was referred to pediatric oncology and urology for suspicion of a tumorous mass and the condition was assessed as a cystic nephroma. A heminephrectomy was then performed on the upper cystic part of the right kidney. The histological examination was inconclusive; therefore, genetic testing was recommended. Kidney and liver cysts were detected sonographically in the mother, but DNA analysis of the PKD1 and PKD2 genes did not reveal any pathogenic variant; the cause of the pathological formation in the kidneys remained unclear. Nine years later, next-generation sequencing of a panel of genes for kidney disease was performed and a heterozygous deletion was found on chromosome 16; this included exon 13 of the IFT140 gene. The same deletion was found in the patient's mother. Currently, the patient is 14 years old and has mild sonographic findings, normal glomerular filtration, mild proteinuria, and hypertension.

Conclusion

Pathogenic variants of the IFT140 gene very rarely cause ADPKD; however, they should be considered in all children with autosomal dominant forms of PKD and asymmetric/atypical cystic kidney involvement or negative findings of PKD1 and PKD2.

[New beta0-thalassaemic insertion mutation (CD 7/8, +G) in a Slovak family, associated with the Mediterranean haplotype IX]

The authors describe a newly identified beta0-thalassaemic mutation found in two subjects from two generations of a Slovak family. The beta0-thalassaemic allele developed by insertion of one nucleotide (+G, CD 7/8) into the first exon of the beta-globin gene. The mutation causes a shift of the open globin reading frame which leads to the development of a terminal codon in codon 22. The thalassaemic allele is associated with the mediterranean haplotype IX. The mutation has in both heterozygotes the phenotype of beta0-thalassaemia minor with a slightly elevated level of HbF.

[Comparison between femoropopliteal bypass and subintimal recanalization in the treatment of critical limb ischaemia]

INTRODUCTION

Revascularization of occlusion of the femoropopliteal region in patients with critical limb ischaemia (CLI) may be performed following the standard surgical approach using bypass with the saphenous vein graft (FP bypass). Unfortunately, up to 40% of these patients do not have a suitable saphenous vein. In these patients, revascularization may be performed surgically using bypass with prosthesis, allograft vein or by interventional radiological methods. An endovascular alternative is represented by subintimal recanalization (SIR).

MATERIAL AND METHODS

Our prospective analysis evaluated mid-term results of revascularization using FP bypass or SIR in patients with occlusion of the femoropopliteal region and CLI. Our aim was to answer the question whether SIR can fully replace FP bypass in certain indications. From January 2010 to December 2012, 59 revascularizations of the CLI (Rutherford 5-6) with comparable SFA occlusion were performed. We monitored the immediate postoperative course, technical and clinical success and the process of healing of the defect.

RESULTS

Healing of the defect was achieved in 78.6% of patients with FP bypass using the saphenous vein, in 62.5% of patients with FP bypass using prosthesis and in 64.9% of patients with SIR (P=0.578). When comparing the bypass group, which was subdivided into a group with revascularization using autologous vein and a group with revascularization using ePTFE prosthesis, with the SIR group, primary patency was evaluated. The results for vein 78.0% after 6, 12, 24 and 36 months, for prosthesis 74.5%, 55%, 55% after 6, 12 and 24 months, and for the SIR group 78%, 60%, 51.3% and 50.7% after 6,12,24 and 36 months. When comparing the results of the groups, no statistically significant difference was found (P =0.625).

CONCLUSION

As expected, the most successful method of choice is revascularization by FPB using the saphenous vein. SIR and FP bypass using prosthesis had similar results with respect to healing of the defects.