Inherited ichthyoses: molecular causes of the disease in Czech patients.

Inherited ichthyoses belong to a large and heterogeneous group of mendelian disorders of cornification, and can be distinguished by the quality and distribution of scaling and hyperkeratosis, by other dermatologic and extracutaneous involvement, and by inheritance. We present the genetic analysis results of probands with X-linked ichthyosis, autosomal recessive congenital ichthyosis, keratinopathic ichthyosis, and a patient with Netherton syndrome. Genetic diagnostics was complemented by in silico missense variant analysis based on 3D protein structures and commonly used prediction programs to compare the yields of these two approaches to each other. This analysis revealed various structural defects in proteins coded by mutated genes while no defects were associated with known polymorphisms. Two patients with pathogenic variants in the ABCA12 gene have a premature termination codon mutation on one allele and a silent variant on the second. The silent variants c.69G > A and c.4977G > A are localised in the last nucleotide of exon 1 and exon 32, respectively, and probably affect mRNA splicing. The phenotype of both patients is very severe, including a picture harlequin foetus after birth; later (at 3 and 6 years of age, respectively) ectropin, eclabion, generalised large polygonal scaling and erythema.

Genome-wide uniparental diploidy of all paternal chromosomes in an 11-year-old girl with deafness and without malignancy.

Approximately 20 cases of genome-wide uniparental disomy or diploidy (GWUPD) as mosaicism have previously been reported. We present the case of an 11-year-old deaf girl with a paternal uniparental diploidy or isodisomy with a genome-wide loss of heterozygosity (LOH). The patient was originally tested for non-syndromic deafness, and the novel variant p.V234I in the ESRRB gene was found in a homozygous state. Our female proband is the seventh patient diagnosed with GWUPD at a later age and is probably the least affected of the seven, as she has not yet presented any malignancy. Most, if not all, reported patients with GWUPD whose clinical details have been published have developed malignancy, and some of those patient developed malignancy several times. Therefore, our patient has a high risk of malignancy and is carefully monitored by a specific outpatient pediatric oncology program. This observation seems to be novel and unique in a GWUPD patient. Our study is also unique as it not only provides very detailed documentation of the genomic situations of various tissues but also reports differences in the mosaic ratios between the blood and saliva, as well as a normal biparental allelic situation in the skin and biliary duct. Additionally, we were able to demonstrate that the mosaic ratio in the blood remained stable even after 3 years and has not changed over a longer period.

Association of 17q24.2-q24.3 deletions with recognizable phenotype and short telomeres.

Microdeletions of 17q24.2-q24.3 have been described in several patients with developmental and speech delay, growth retardation, and other features. The relatively large size and limited overlap of the deletions complicate the genotype-phenotype correlation. We identified a girl with intellectual disability, growth retardation, dysmorphic features, and a de novo 2.8 Mb long deletion of 17q24.2-q24.3. Her phenotype was strikingly similar to one previously described boy with Dubowitz syndrome (MIM 223370) and a de novo 3.9 Mb long deletion encompassing the deletion of our patient. In addition, both patients had the shortest telomeres among normal age-matched controls. Our review of all 17q24.2-q24.3 deletion patients revealed additional remarkable phenotypic features shared by the patients, some of which have consequences for their management. Proposed novel genotype-phenotype correlations based on new literature information on the region include the role of PSMD12 and BPTF, the genes recently associated with syndromic neurodevelopmental disorders, and a possible role of the complex topologically associated domain structure of the region, which may explain some of the phenotypic discrepancies observed between patients with similar but not identical deletions. Nevertheless, although different diagnoses including the Dubowitz, Nijmegen breakage (MIM 251260), Silver-Russell (MIM 180860), or Myhre (MIM 139210) syndromes were originally considered in the 17q24.2-q24.3 deletion patients, they clearly belong to one diagnostic entity defined by their deletions and characterized especially by developmental delay, specific facial dysmorphism, abnormalities of extremities and other phenotypes, and possibly also short telomere length.

Cutis laxa and excessive bone growth due to de novo mutations in PTDSS1.

The cutis laxa syndromes are multisystem disorders that share loose redundant inelastic and wrinkled skin as a common hallmark clinical feature. The underlying molecular defects are heterogeneous and 13 different genes have been involved until now, all of them being implicated in elastic fiber assembly. We provide here molecular and clinical characterization of three unrelated patients with a very rare phenotype associating cutis laxa, facial dysmorphism, severe growth retardation, hyperostotic skeletal dysplasia, and intellectual disability. This disorder called Lenz-Majewski syndrome (LMS) is associated with gain of function mutations in PTDSS1, encoding an enzyme involved in phospholipid biosynthesis. This report illustrates that LMS is an unequivocal cutis laxa syndrome and expands the clinical and molecular spectrum of this group of disorders. In the neonatal period, brachydactyly and facial dysmorphism are two early distinctive signs, later followed by intellectual disability and hyperostotic skeletal dysplasia with severe dwarfism allowing differentiation of this condition from other cutis laxa phenotypes. Further studies are needed to understand the link between PTDSS1 and extra cellular matrix assembly.

Odontogenic keratocysts in the Basal Cell Nevus (Gorlin-Goltz) Syndrome associated with paresthesia of the lower jaw: Case report, retrospective analysis of a representative Czech cohort and recommendations for the early diagnosis.

OBJECTIVES: Identification of early presenting signs of the Basal Cell Nevus (BCNS; synonyme Gorlin-Goltz) syndrome, which is associated with a principal triad of multiple basal cell nevi, jaw odontogenic keratocysts, and skeletal anomalies, in stomatological and neurological practices. Proposal of multidisciplinary diagnostic algorithm comprising other medical specialists, including pathology, imaging, laboratory and molecular analyses based on the study outcomes. DESIGN: Case report of a male patient reporting paresthesia of their lower jaw, with right facial asymmetry (maxilla and mandible) and radiological detection of large osteolytic lesions in both jaws, including a retrospective analysis of a representative Czech cohort with BCNS from within the last decade. SETTING: Clinical, imaging and laboratory analyses were carried out at a national tertiary centre. RESULTS: A multidisciplinary clinical approach followed by surgical management lead to the identification of odontogenic cysts, which were substantiated by histological examination. DNA sequencing of the PTCH1 gene detected a c.2929dupT resulting in p. Tyr977Leufs*16 pathogenic variant. This finding confirmed the clinical and laboraoty diagnosis of BCNS. Parental DNA analysis showed that this causal genetic defect arose de novo. Surgical management and orthodontic therapy were successful. CONCLUSIONS: Analysis of the reported case and retrospective data analysis provided evidence that paresthesia of the lower jaw should be considered as one of the early presenting signs of this rare disorder in stomatological and neurological practice. Obtained results allowed us to formulate recommendations for diagnostic practice in stomatology and neurology.

Spectrum and frequency of SLC26A4 mutations among Czech patients with early hearing loss with and without Enlarged Vestibular Aqueduct (EVA).

Mutations in SLC26A4 cause Pendred syndrome (PS) - hearing loss with goitre - or DFNB4 - non-syndromic hearing loss (NSHL) with inner ear abnormalities such as Enlarged Vestibular Aqueduct (EVA) or Mondini Dysplasia (MD). We tested 303 unrelated Czech patients with early hearing loss (298 with NSHL and 5 with PS), all GJB2-negative, for SLC26A4 mutations and evaluated their clinical and radiological phenotype. Among 115 available HRCT/MRI scans we detected three MD (2.6%), three Mondini-like affections (2.6%), 16 EVA (13 bilateral - 19.2% and 15.6% respectively) and 61 EVA/MD-negative scans (73.4%). We found mutation(s) in 26 patients (8.6%) and biallelic mutations in eight patients (2.7%) out of 303 tested. In 18 of 26 (69%) patients, no second mutation could be detected even using MLPA. The spectrum of SLC26A4 mutations in Czech patients is broad without any prevalent mutation. We detected 21 different mutations (four novel). The most frequent mutations were p.Val138Phe and p.Leu445Trp (18% and 8.9% of pathogenic alleles respectively). Among 13 patients with bilateral EVA, six patients (50%) carry biallelic mutations. In EVA -negative patients no biallelic mutations were found but 4.9% had monoallelic mutations. SLC26A4 mutations are present mostly in patients with EVA/MD and/or progressive HL and those with affected siblings.

Polycystic kidney and hepatic disease with mental retardation and hand anomalies in three siblings.

A family with three children affected with congenital polycystic kidneys, hepatic fibrosis, mental retardation, minor anomalies of the hands, and dysmorphic facial features is reported. All children progressed to chronic renal failure. Linkage to the locus for autosomal recessive polycystic kidney disease was excluded by haplotype analysis. The family is endogamic, and the affected siblings are of both sexes, which is in agreement with an autosomal recessive determination of this syndrome. A similar syndrome was reported in 1990 by Labrune et al. [J Pediatr Gastroenterol Nutr (1990) 10:540-543]. Our report provides further evidence for the etiological heterogeneity of polycystic kidney with hepatic fibrosis. The syndrome reported here should be considered in the differential diagnosis of the early manifestation of polycystic kidneys. Mental retardation and hand anomalies are the hallmarks for the differential diagnosis of this syndrome.

Some ADHD polymorphisms (in genes DAT1, DRD2, DRD3, DBH, 5-HTT) in case-control study of 100 subjects 6-10 age.

BACKGROUND: Pharmacological approach is the most effective way of treatment of ADHD and its early application prevents from the progress of secondary disorders. The study on present neurotransmitter systems in pathology of ADHD can be helpful in selecting appropriate drug, since there are used various substances with different mechanisms of functioning in treatment of the hyperkinetic syndrome. METHOD: Within our study there were selected the genes of dopaminergic (DRD2, DRD3, DAT1), noradrenergic (DBH) and serotoninergic (5-HTT) systems. With the use of molecular-genetic methods based on association strategy "case-control" there were analysed genes including 11 polymorphisms. The presence of risk alleles was examined in comparison of the sample of 100 ADHD children to a control group of another 100 subjects, who were checked by child psychiatrists and examined with the Conners test in order to exclude eventual cases with ADHD symptoms. RESULTS: Our research suggests the association of some genes with ADHD. It could be concluded: 1) the risk of ADHD is significantly increased in the presence of one risk allele in genes DRD2 (O.R.=7,5), 5-HTT (O.R.=2,7) and DAT1 (O.R.=1,6). 2) The risk of ADHD is significantly increased at homozygotes for risk alleles in genes DRD2 (O.R.=54,8), 5-HTT (O.R.=6,7) and DAT1 (O.R.=6,6). For polymorphisms G444A and C1603T in DBH, which were detected by univariant analysis, haplotype analysis was performed and resulted in conclusion that: 3) the risk of ADHD is significantly increased in the presence of allele DBH +444A as well as in the presence of allele DBH +1603T (O.R.=15).

A novel Czech kindred with familial medullary thyroid carcinoma and Hirschsprung's disease.

PURPOSE: The RET proto-oncogene is involved in neural crest disorders. Activating germline mutations in the RET proto-oncogene cause the development of familial medullary thyroid carcinoma (FMTC) or medullary thyroid carcinoma (MTC) as a part of multiple endocrine neoplasia type 2 (MEN2) syndrome. Inactivating germline mutations in the RET proto-oncogene are detected in Hirschsprung's disease (HSCR). Only in a very small number of families are these 2 diseases expressed together. METHODS: This study presents a novel Czech kindred with FMTC-HSCR phenotype. Two family members (mother and daughter) were tested for RET germline mutations in exons 10, 11, 13, 14, 15, and 16. RESULTS: Direct fluorescent sequencing of genomic DNA revealed a heterozygous mutation in the RET proto-oncogene in exon 10 at codon C609Y in both persons tested. This family was reclassified, thanks to genetic screening from the apparently sporadic MTC-HSCR to FMTC-HSCR. CONCLUSION: The germline mutation was detected because of the systematic genetic screening of the RET proto-oncogene, which is useful for genetic counseling of potential risk of HSCR and MTC in other family members. This family could be added to the small worldwide cohort of families with MEN2A/FMTC-HSCR.