A 22q11.2-microdeletiós szindróma klinikai jellemzői

Összefoglaló. Bevezetés: A sokszínű tünetspektrummal jellemezhető DiGeorge-szindróma leggyakoribb oka a 22q11.2-microdeletio; incidenciája 1/4000–6000. Célkitűzés: A DiGeorge-szindrómára gyanús hazai betegcsoport 22q11.2-microdeletióval társult tüneteinek/panaszainak részletes feltérképezése, a betegség incidenciájának becslése és egy magyarországi 22q11.2-microdeletiós szindróma regiszter létrehozása. Módszer: 2005 és 2019 között a Semmelweis Egyetem II. Gyermekgyógyászati Klinikájára DiGeorge-szindróma gyanújával beutalt és a Veleszületett Rendellenességek Országos Nyilvántartása által regisztrált DiGeorge-szindrómás betegek adatait dolgoztuk fel. A fenotípusjegyeket a Humán Fenotípus Ontológia kódrendszer alapján határoztuk meg. Eredmények: A vizsgálatba 114, igazolt DiGeorge-szindrómás és 113, FISH-vizsgálattal microdeletiót nem hordozó, de klinikailag a DiGeorge-szindróma tüneteit mutató beteget vontunk be. A diagnózis felállításakor a betegek átlagéletkora 5,88 (± 9,66 SD) év volt, eddig a betegek 54,9%-a legalább egy szívműtéten átesett. A betegek leggyakoribb tünetei a kamrai sövényhiány, a mélyen ülő fülek, a gótikus szájpad, a motoros fejlődési elmaradás és a visszatérő fertőzések voltak. Megbeszélés: A DiGeorge-szindróma becsült incidenciája hazánkban 1/12 500, közöttük magas a többszörösen veszélyeztetett újszülöttek és a műtéti korrekcióra szorulók aránya. A diagnózis hazánkban 2–3 évvel korábban történik a nemzetközi átlaghoz viszonyítva. Következtetés: A létrehozott regiszterünk alapján Magyarországon a kórkép aluldiagnosztizált. Minden conotruncalis szívfejlődési rendellenesség vagy jelentős kamrai sövényhiány esetén citogenetikai vizsgálat javasolt a DiGeorge-szindróma felmerülő gyanúja miatt. Negatív lelet esetén az atípusos töréspontú microdeletiók azonosítására komparatív genomiális hibridizáció vagy multiplex ligatiofüggő próbaamplifikációs vizsgálat javasolt. A betegek számára multidiszciplináris ellátás szükséges, III-as progresszivitási szintű újszülött intenzív részlegen, gyermekkardiológus és klinikai genetikus részvételével. Orv Hetil. 2022; 163(1): 21–30. Summary. Introduction: The 22q11.2 microdeletion syndrome is the most common cause of DiGeorge syndrome, showing a wide phenotypic spectrum and has an estimated incidence of 1/4000–6000 livebirths. Objective: Detailed characterization of the clinical signs/symptoms associated with 22q11.2 deletion, estimation of the national incidence via establishing a Hungarian register. Method: Retrospective data between 2005 and 2019 from the 2nd Department of Paediatrics, Semmelweis University and from national database of congenital anomalies were obtained. Phenotypic abnormalities were described using the Human Phenotype Ontology nomenclature. Results: A cohort of 114 DiGeorge patients and 113 patients negative for FISH testing were included. The mean age of patients at diagnosis was 5.88 (± 9.66 SD) years and 54.9% of patients had at least one heart surgery until diagnosis. The main identified symptoms were ventricular septal defect, low-set ears, recurrent infections, high narrow palate and motor development delay. Discussion: The estimated incidence of DiGeorge syndrome in Hungary is 1/12 500 births, the frequency of infants at high risk and in need for surgery is high. Diagnosis is established 2–3 years earlier as compared to the international average. Conclusion: Based on the established Hungarian register, the incidence is lower compared to international data. In the case of conotruncal heart anomaly and ventricular septal defects, cytogenetic testing is recommended for the increased probability of DiGeorge syndrome. For second-tier testing, comparative genome hybridization or multiplex ligation-dependent probe amplification are recommended to identify atypical microdeletions. Newborns with DiGeorge syndrome require special care in perinatal intensive centers including pediatric cardiology and genetic counseling. Orv Hetil. 2022; 163(1): 21–30.

MPC-13 The evaluation of the shift of trend in lower grade glioma diagnoses based on each era`s criteria

It is found that molecular characteristics in lower grade gliomas (LrGGs) such as codeletion of 1p/19q and IDH mutation was found to be more accurate to predict the patient`s clinical outcome compared to morphological diagnoses alone. Since the revision WHO2016 classification of LrGGs, molecular characteristics were implemented as diagnostic standard for LrGGs diagnoses. In the other hand, morphological diagnostic standard before WHO2016 classification era was determined by different considerations and therapeutic strategies. The malignancy grades were also majorly determined by morphological diagnoses only. This study re-evaluated 20 years of LrGG cases in single institution based on WHO2007 morphological criteria and compared them to the original institutional diagnoses from each era. The study samples were originally grade II-III diffuse glioma-diagnosed cases resected from 1990 to 2016. Biopsy cases were excluded. IDH mutation was analyzed by Sanger sequence and 1p/19 codeletion status was analyzed by Comparative Genome Hybridization (CGH). As the result 93 cases were collected and based on original diagnoses, more than 50% cases are astrocytomas. Compared to re-assessment by morphological diagnoses (WHO 2007), case numbers of astrocytoma diagnoses are decreased whereas oligodendroglioma and oligoastrocytoma case numbers are increased. But, based on WHO2016 criteria, the case number of astrocytomas is again found to be increased. From comparison between original institutional diagnoses and re-assessment results, it is found that there is a shift of trend from astrocytoma to oligodendroglioma and from grade II to grade III. Comparison between morphological diagnoses (WHO2007) and molecular (WHO2016) found that astrocytoma diagnoses remain unchanged meanwhile 45% of oligodendroglioma diagnoses were shifted into astrocytomas. There is a probability that there are high frequency of morphologically diagnosed oligodendroglioma tumors which are having molecular characteristics of astrocytoma. There is a trend that diagnosed grade II LrGGs are actually grade III based on re-assessment diagnosis.

Azoospermia and reciprocal translocations: should whole-exome sequencing be recommended?

Background Although chromosome rearrangements are responsible for spermatogenesis failure, their impact depends greatly on the chromosomes involved. At present, karyotyping and Y chromosome microdeletion screening are the first-line genetic tests for patients with non-obstructive azoospermia. Although it is generally acknowledged that X or Y chromosome rearrangements lead to meiotic arrest and thus rule out any chance of sperm retrieval after a testicular biopsy, we currently lack markers for the likelihood of testicular sperm extraction (TESE) in patients with other chromosome rearrangements. Results We investigated the use of a single nucleotide polymorphism comparative genome hybridization array (SNP-CGH) and whole-exome sequencing (WES) for two patients with non-obstructive azoospermia and testicular meiotic arrest, a reciprocal translocation: t(X;21) and t(20;22), and an unsuccessful TESE. No additional gene defects were identified for the t(X;21) carrier - suggesting that t(X;21) alone damages spermatogenesis. In contrast, the highly consanguineous t(20;22) carrier had two deleterious homozygous variants in the TMPRSS9 gene; these might have contributed to testicular meiotic arrest. Genetic defect was confirmed with Sanger sequencing and immunohistochemical assessments on testicular tissue sections. Conclusions Firstly, TMPRSS9 gene defects might impact spermatogenesis. Secondly, as a function of the chromosome breakpoints for azoospermic patients with chromosome rearrangements, provision of the best possible genetic counselling means that genetic testing should not be limited to karyotyping. Given the risks associated with TESE, it is essential to perform WES - especially for consanguineous patients.

Tracking the Evolutionary Trends Among Small-Size Fishes of the Genus Pyrrhulina (Characiforme, Lebiasinidae): New Insights From a Molecular Cytogenetic Perspective

Miniature fishes have always been a challenge for cytogenetic studies due to the difficulty in obtaining chromosomal preparations, making them virtually unexplored. An example of this scenario relies on members of the family Lebiasinidae which include miniature to medium-sized, poorly known species, until very recently. The present study is part of undergoing major cytogenetic advances seeking to elucidate the evolutionary history of lebiasinids. Aiming to examine the karyotype diversification more deeply in Pyrrhulina, here we combined classical and molecular cytogenetic analyses, including Giemsa staining, C-banding, repetitive DNA mapping, comparative genomic hybridization (CGH), and whole chromosome painting (WCP) to perform the first analyses in five Pyrrhulina species (Pyrrhulina aff. marilynae, Pyrrhulina sp., P. obermulleri, P. marilynae and Pyrrhulina cf. laeta). The diploid number (2n) ranged from 40 to 42 chromosomes among all analyzed species, but P. marilynae is strikingly differentiated by having 2n = 32 chromosomes and a karyotype composed of large meta/submetacentric chromosomes, whose plesiomorphic status is discussed. The distribution of microsatellites does not markedly differ among species, but the number and position of the rDNA sites underwent significant changes among them. Interspecific comparative genome hybridization (CGH) found a moderate divergence in the repetitive DNA content among the species’ genomes. Noteworthy, the WCP reinforced our previous hypothesis on the origin of the X1X2Y multiple sex chromosome system in P. semifasciata. In summary, our data suggest that the karyotype differentiation in Pyrrhulina has been driven by major structural rearrangements, accompanied by high dynamics of repetitive DNAs.

Terminal 10q26.12 deletion is associated with neonatal asymmetric crying facies syndrome: a case report and literature review

Background The terminal 10q26 deletion syndrome is a clinically heterogeneous disorder without identified genotype–phenotype correlations. We reported a case of congenital asymmetric crying facies (ACF) syndrome with 10q26.12qter deletion and discussed their genotype–phenotype correlations and the potentially contributing genes involving the etiology of ACF. Methods and results We reported a case of neonatal 10q26.12qter deletion and summarized the genotype–phenotype correlations and contributing genes of 10q26.12qter deletion from DECIPHER database and published studies. Meanwhile, we analyzed the potential pathogenic genes contributing to 10q26 deletion syndrome. The female preterm infant harboring 10q26.12qter deletion showed symptoms of abnormal craniofacial appearance with rare congenital asymmetric crying facies, developmental retardation, congenital heart disease, and pulmonary artery hypertension. The deleted region was 13.28 Mb in size as detected by G-banding and array comparative genome hybridization, containing 62 Online Mendelian Inheritance in Man (OMIM) catalog genes. We summarized data from 17 other patients with 10q26.12qter deletion, 11 from the DECIPHER database and 6 from published studies. Patients with monoallelic WDR11 and FGFR2 deletions located in 10q26.12q26.2 were predisposed to craniofacial dysmorphisms, growth retardation, intellectual disability and cardiac diseases. Conclusion ACF is a facial dysmorphism frequently accompanied by other systemic deformities. It is a genetic abnormality that may associate with terminal 10q26.12 deletion. Early cardiac, audiologic, cranial examinations and genetic detection are needed to guide early diagnosis and treatment strategy.

Cytogenetic Evidence for Sex Chromosomes and Karyotype Evolution in Anguimorphan Lizards

Anguimorphan lizards are a morphologically variable group of squamate reptiles with a wide geographical distribution. In spite of their importance, they have been cytogenetically understudied. Here, we present the results of the cytogenetic examination of 23 species from five anguimorphan families (Anguidae, Helodermatidae, Shinisauridae, Varanidae and Xenosauridae). We applied both conventional (Giemsa staining and C-banding) and molecular cytogenetic methods (fluorescence in situ hybridization with probes for the telomeric motifs and rDNA loci, comparative genome hybridization), intending to describe the karyotypes of previously unstudied species, to uncover the sex determination mode, and to reveal the distribution of variability in cytogenetic characteristics among anguimorphan lizards. We documented that karyotypes are generally quite variable across anguimorphan lineages, with anguids being the most varying. However, the derived chromosome number of 2n = 40 exhibits a notable long-term evolutionary stasis in monitors. Differentiated ZZ/ZW sex chromosomes were documented in monitors and helodermatids, as well as in the anguids Abronia lythrochila, and preliminary also in Celestus warreni and Gerrhonotus liocephalus. Several other anguimorphan species have likely poorly differentiated sex chromosomes, which cannot be detected by the applied cytogenetic methods, although the presence of environmental sex determination cannot be excluded. In addition, we uncovered a rare case of spontaneous triploidy in a fully grown Varanus primordius.

Revisiting the Karyotypes of Alligators and Caimans (Crocodylia, Alligatoridae) after a Half-Century Delay: Bridging the Gap in the Chromosomal Evolution of Reptiles

Although crocodilians have attracted enormous attention in other research fields, from the cytogenetic point of view, this group remains understudied. Here, we analyzed the karyotypes of eight species formally described from the Alligatoridae family using differential staining, fluorescence in situ hybridization with rDNA and repetitive motifs as a probe, whole chromosome painting (WCP), and comparative genome hybridization. All Caimaninae species have a diploid chromosome number (2n) 42 and karyotypes dominated by acrocentric chromosomes, in contrast to both species of Alligatorinae, which have 2n = 32 and karyotypes that are predominantly metacentric, suggesting fusion/fission rearrangements. Our WCP results supported this scenario by revealing the homeology of the largest metacentric pair present in both Alligator spp. with two smaller pairs of acrocentrics in Caimaninae species. The clusters of 18S rDNA were found on one chromosome pair in all species, except for Paleosuchus spp., which possessed three chromosome pairs bearing these sites. Similarly, comparative genomic hybridization demonstrated an advanced stage of sequence divergence among the caiman genomes, with Paleosuchus standing out as the most divergent. Thus, although Alligatoridae exhibited rather low species diversity and some level of karyotype stasis, their genomic content indicates that they are not as conserved as previously thought. These new data deepen the discussion of cytotaxonomy in this family.

Clinical Cytogenetics of the Dog: A Review

The dog is an important companion animal and has been recognized as a model in biomedical research. Its karyotype is characterized by a high chromosome number (2n = 78) and by the presence of one-arm autosomes, which are mostly small in size. This makes the dog a difficult subject for cytogenetic studies. However, there are some chromosome abnormalities that can be easily identified, such as sex chromosome aneuploidies, XX/XY leukocyte chimerism, and centric fusions (Robertsonian translocations). Fluorescence in situ hybridization (FISH) with the use of whole-chromosome painting or locus-specific probes has improved our ability to identify and characterize chromosomal abnormalities, including reciprocal translocations. The evaluation of sex chromosome complement is an important diagnostic step in dogs with disorders of sex development (DSD). In such cases, FISH can detect the copy number variants (CNVs) associated with the DSD phenotype. Since cancers are frequently diagnosed in dogs, cytogenetic evaluation of tumors has also been undertaken and specific chromosome mutations for some cancers have been reported. However, the study of meiotic, gamete, and embryo chromosomes is not very advanced. Knowledge of canine genome organization and new molecular tools, such as aCGH (array comparative genome hybridization), SNP (single nucleotide polymorphism) microarray, and ddPCR (droplet digital PCR) allow the identification of chromosomal rearrangements. It is anticipated that the comprehensive use of chromosome banding, FISH, and molecular techniques will substantially improve the diagnosis of chromosome abnormalities in dogs.