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.

A phenotypic rescue approach identifies lineage regionalization defects in a mouse model of DiGeorge syndrome

ABSTRACTTBX1 is a key regulator of pharyngeal apparatus (PhAp) development. Vitamin B12 treatment partially rescues aortic arch patterning defects of Tbx1+/- embryos. Here we show that it also improves cardiac outflow tract septation and branchiomeric muscle anomalies of Tbx1 hypomorphic mutants. At molecular level, the in vivo vB12 treatment let us to identify genes that were dysregulated by Tbx1 haploinsufficiency and rescued by treatment. We found that SLUG, encoded by the rescued gene Snai2, identified a population of mesodermal cells that was partially overlapping with but distinct from ISL1+ and TBX1+ populations. In addition, SLUG+ cells were mislocalized and had a greater tendency to aggregate in Tbx1+/- and Tbx1-/- embryos and vB12 treatment restore cellular distribution. Adjacent neural crest-derived mesenchymal cells, which do not express TBX1, were also affected, showing enhanced segregation from cardiopharyngeal mesodermal cells. We propose that TBX1 regulates cell distribution in core mesoderm and the arrangement of multiple lineages within the PhAp.

Reply to: Noninvasive prenatal testing for DiGeorge syndrome: is it ready for clinical practice?

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Noninvasive prenatal testing for DiGeorge syndrome: is it ready for clinical practice?

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Scoliosi da ortopedico perché sindromiche

The paper describes two cases of DiGeorge syndrome and syndromic scoliosis. In the first one, the delay of the surgical intervention significantly compromised the quality of life and the final result. The author stresses the importance of a prompt surgery in every syndromic scoliosis.

Taiwanese Clinical Experience with Noninvasive Prenatal Testing for DiGeorge Syndrome

<b><i>Objective:</i></b> DiGeorge syndrome (DGS) is associated with microdeletions of chromosome 22q11. It is the second most common cause of congenital heart disease and is an important consideration whenever a conotruncal cardiac anomaly is identified. The availability of noninvasive prenatal testing (NIPT) is altering the practice of prenatal genetics and maternal-fetal medicine, resulting in a decline in invasive testing. Antenatal ultrasound and other biomarkers have their own limitation. NIPT was proposed to screen DGS with cell-free DNA in Taiwan. Here, we present our experience of prenatal diagnosis of DGS in our center. <b><i>Methods:</i></b> This was a retrospective study between November 1, 2019, and August 31, 2020, in Taiwan. Data were collected from 7,826 pregnant women self-referred for DGS screening with massive parallel shotgun sequencing-based NIPT. High-risk cases subsequently received amniocentesis for array comparative genomic hybridization (aCGH) to confirm the diagnosis. Characteristics of pregnancies were documented when participants received the test. Report of NIPT was completed 2 weeks after the test. Follow-up on high-risk cases was completed by telephone interview on January 30, 2021. <b><i>Results:</i></b> Thirteen cases showed high risk by NIPT, and 7 cases were confirmed by aCGH. The sensitivity and specificity were 100% (95% confidence interval [CI] 64.57–100.00%) and 99.92% (95% CI 99.83–99.96%). The prevalence of DGS was 1 in 1,118 pregnancies. The positive predictive rate was 53.85% (95% CI 29.14–76.79%). One true positive (TP) showed US anomaly, and 5 TPs selected termination. <b><i>Discussion/Conclusion:</i></b> NIPT demonstrated good performance in DGS screening. Detection of 22q11.2 deletion could be combined with routine screening to facilitate proper intervention.