Chromosomal band 17q12 is a gene-rich region flanked by segmental duplications, making the region prone to deletions and duplications via the non-allelic homologous recombination mechanism. While deletions cause a well-described disorder with a specific phenotype called renal cysts and diabetes mellitus, the phenotype caused by reciprocal duplications is less specific, primarily because of variable expressivity, and incomplete penetrance. We present an unusual family with four children carrying the 17q12 microduplication inherited from their clinically healthy mother, who was a carrier of both the duplication and, interestingly, also of an atypical deletion of the 17q12 region. The duplication was inherited from her diabetic father and the deletion from her diabetic mother who also suffered from a renal disorder. Clinical manifestations in the family were variable, but all children showed some degree of a neurodevelopmental disorder, such as epilepsy, intellectual disability, delayed speech development, or attention deficit disorder. The simultaneous occurrence of a deletion and duplication in the same chromosomal region in one family is very rare, and to our knowledge, individuals carrying both a deletion and a duplication of this region have never been described.

• MeSH
• chromozomální delece MeSH
• duplikace chromozomů genetika   MeSH
• fenotyp MeSH
• lidé MeSH
• mentální retardace * genetika   MeSH
• mnohočetné abnormality * genetika   MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• kazuistiky MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH

BACKGROUND AND AIM: Gene defects contribute to the aetiology of intrahepatic cholestasis. We aimed to explore the outcome of whole-exome sequencing (WES) in a cohort of 51 patients with this diagnosis. PATIENTS AND METHODS: Both paediatric (n = 33) and adult (n = 18) patients with cholestatic liver disease of unknown aetiology were eligible. WES was used for reassessment of 34 patients (23 children) without diagnostic genotypes in ABCB11, ATP8B1, ABCB4 or JAG1 demonstrable by previous Sanger sequencing, and for primary assessment of additional 17 patients (10 children). Nasopharyngeal swab mRNA was analysed to address variant pathogenicity in two families. RESULTS: WES revealed biallelic variation in 3 ciliopathy genes (PKHD1, TMEM67 and IFT172) in 4 clinically unrelated index subjects (3 children and 1 adult), heterozygosity for a known variant in PPOX in one adult index subject, and homozygosity for an unreported splice-site variation in F11R in one child. Whereas phenotypes of the index patients with mutated PKHD1, TMEM67, and PPOX corresponded with those elsewhere reported, how F11R variation underlies liver disease remains unclear. Two unrelated patients harboured different novel biallelic variants in IFT172, a gene implicated in short-rib thoracic dysplasia 10 and Bardet-Biedl syndrome 20. One patient, a homozygote for IFT172 rs780205001 c.167A>C p.(Lys56Thr) born to first cousins, had liver disease, interpreted on biopsy aged 4y as glycogen storage disease, followed by adult-onset nephronophthisis at 25y. The other, a compound heterozygote for novel frameshift variant IFT172 NM_015662.3 c.2070del p.(Met690Ilefs*11) and 2 syntenic missense variants IFT172 rs776310391 c.157T>A p.(Phe53Ile) and rs746462745 c.164C>G p.(Thr55Ser), had a severe 8mo cholestatic episode in early infancy, with persisting hyperbilirubinemia and fibrosis on imaging studies at 17y. No patient had skeletal malformations. CONCLUSION: Our findings suggest association of IFT172 variants with non-syndromic cholestatic liver disease.

• MeSH
• adaptorové proteiny signální transdukční genetika   MeSH
• cholestáza * genetika   MeSH
• cytoskeletální proteiny genetika   MeSH
• flavoproteiny genetika   MeSH
• genotyp MeSH
• intrahepatální cholestáza * genetika   diagnóza   MeSH
• lidé MeSH
• mitochondriální proteiny genetika   MeSH
• mutace MeSH
• protoporfyrinogenoxidasa genetika   MeSH
• sekvenování exomu MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Downův syndrom (DS) patří mezi nejčastější vrozené syndromy vyskytující se v lidské populaci. Příčinou DS je úplná nebo částečná trizomie chromozomu 21. Onemocnění je provázeno typickým fenotypovým projevem a vyšším rizikem zdravotních komplikací, vč. hemato-onkologických onemocnění. Mezi nejzávažnější hematologické komplikace patří tranzientní myeloproliferativní onemocnění (TMD), myelodysplastický syndrom a akutní leukemie. TMD postihuje až 10 % novorozenců s DS. Ve většině případů dochází ke spontánní remisi onemocnění, avšak ve 20–30 % případů dojde k rozvoji akutní leukemie. Akutní leukemie spojená s DS bývá nejčastěji myeloidního původu a vzácně lymfoidního původu. TMD není definováno jednoznačnými morfologickými kritérii. Jedná se o tranzientní stav přítomnosti blastů megakaryocytární linie v periferní krvi u dětí s trizomií chromozmomu 21.

Down syndrome (DS) is one of the most common congenital syndromes in humans. The cause of DS is complete or partial trisomy of chromosome 21. The disease is associated with a typical phenotypic manifestation and a higher risk of health complications, including haemato-oncological diseases. The most serious haematological complications include transient myeloproliferative disease (TMD), myelodysplastic syndrome and acute leukaemia. TMD affects up to 10% of new-borns with DS. While spontaneous remission occurs in most cases, 20–30% of cases develop into acute leukaemia. Acute leukaemia associated with DS is most often of myeloid origin, rarely of lymphoid origin. TMD is not defined by unambiguous morphological criteria and characterised by the transient presence of megakaryocyte lineage blasts in the peripheral blood of children with chromosome 21 trisomy.

• MeSH
• akutní lymfatická leukemie diagnóza   krev   MeSH
• dítě MeSH
• Downův syndrom * diagnóza   genetika   komplikace   MeSH
• hematologické testy metody   MeSH
• lidé MeSH
• myeloproliferativní poruchy * diagnóza   genetika   krev   MeSH
• předškolní dítě MeSH
• prenatální diagnóza MeSH
• transkripční faktor GATA1 MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• Publikační typ
• kazuistiky MeSH

BACKGROUND: Recently, a study providing insight into GABRB3 mutational spectrum was published (Møller et al 2017). The authors report considerable pleiotropy even for single mutations and were not able to identify any genotype-phenotype correlations. METHODS: The proband (twin B) was referred for massively parallel sequencing of epilepsy-related gene panel because of hypotonia and neonatal seizures. The revealed variant was confirmed with Sanger sequencing in the proband and the twin A, and both parents were tested for the presence of the variant. RESULTS: We report a case of epilepsy of infancy with migrating focal seizures (EIMFS) of neonatal onset in monozygotic twins with a de novo novel GABRB3 variant p.Thr281Ala. The variant has a uniform presentation on an identical genomic background. In addition, early seizure-onset epilepsy associated with GABRB3 mutation has been until now described only for the p.Leu256Gln variant in the GABRB3 (Møller et al 2017, Myers et al 2016) located in the transmembrane domain just as the p.Thr281Ala variant described here. CONCLUSION: De novo GABRB3 mutations may cause neonatal-onset EIMFS with early-onset hypotonia, respiratory distress, and severe developmental delay.

• MeSH
• dvojčata monozygotní genetika   MeSH
• epilepsie farmakoterapie   epidemiologie   genetika   MeSH
• kojenec MeSH
• lidé MeSH
• mutace * MeSH
• nemoci u dvojčat farmakoterapie   epidemiologie   genetika   MeSH
• novorozenec MeSH
• receptory GABA-A genetika   MeSH
• věk při počátku nemoci MeSH
• Check Tag
• kojenec MeSH
• lidé MeSH
• novorozenec MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• práce podpořená grantem MeSH