Molecular and clinical studies in 8 patients with Temple syndrome.

Temple syndrome (TS14, #616222) is a rare imprinting disorder characterised by phenotypic features including pre- and postnatal growth retardation, muscular hypotonia and feeding difficulties in infancy, early puberty and short stature with small hands and feet and often truncal obesity. It is caused by maternal uniparental disomies, paternal deletions and primary imprinting defects that affect the chromosomal region 14q32 and lead to a disturbed expression of imprinted genes in this region. Here, we present detailed clinical data of 8 patients with Temple syndrome, 4 with an imprinting defect, 2 with an imprinting defect in a mosaic state as well as 1 complete and 1 segmental maternal uniparental disomy of chromosome 14.

Broadening of cohesinopathies: exome sequencing identifies mutations in ANKRD11 in two patients with Cornelia de Lange-overlapping phenotype.

Cornelia de Lange syndrome (CdLS) and KBG syndrome are two distinct developmental pathologies sharing common features such as intellectual disability, psychomotor delay, and some craniofacial and limb abnormalities. Mutations in one of the five genes NIPBL, SMC1A, SMC3, HDAC8 or RAD21, were identified in at least 70% of the patients with CdLS. Consequently, additional causative genes, either unknown or responsible of partially merging entities, possibly account for the remaining 30% of the patients. In contrast, KBG has only been associated with mutations in ANKRD11. By exome sequencing we could identify heterozygous loss-of-function mutations in ANKRD11 in two patients with the clinical diagnosis of CdLS. Both patients show features reminiscent of CdLS such as characteristic facies as well as a small head circumference which is not described for KBG syndrome. Patient A, who carries the mutation in a mosaic state, is a 4-year-old girl with features reminiscent of CdLS. Patient B, a 15-year-old boy, shows a complex phenotype which resembled CdLS during infancy, but has developed to a more KBG overlapping phenotype during childhood. These findings point out the importance of screening ANKRD11 in young CdLS patients who were found to be negative for mutations in the five known CdLS genes.

Expanding the clinical spectrum of the 'HDAC8-phenotype' - implications for molecular diagnostics, counseling and risk prediction.

Cornelia de Lange syndrome (CdLS) is a clinically heterogeneous disorder characterized by typical facial dysmorphism, cognitive impairment and multiple congenital anomalies. Approximately 75% of patients carry a variant in one of the five cohesin-related genes NIPBL, SMC1A, SMC3, RAD21 and HDAC8. Herein we report on the clinical and molecular characterization of 11 patients carrying 10 distinct variants in HDAC8. Given the high number of variants identified so far, we advise sequencing of HDAC8 as an indispensable part of the routine molecular diagnostic for patients with CdLS or CdLS-overlapping features. The phenotype of our patients is very broad, whereas males tend to be more severely affected than females, who instead often present with less canonical CdLS features. The extensive clinical variability observed in the heterozygous females might be at least partially associated with a completely skewed X-inactivation, observed in seven out of eight female patients. Our cohort also includes two affected siblings whose unaffected mother was found to be mosaic for the causative mutation inherited to both affected children. This further supports the urgent need for an integration of highly sensitive sequencing technology to allow an appropriate molecular diagnostic, genetic counseling and risk prediction.

Mutations in the homeodomain of the human SIX3 gene cause holoprosencephaly.

Holoprosencephaly (HPE) is a common, severe malformation of the brain that involves separation of the central nervous system into left and right halves. Mild HPE can consist of signs such as a single central incisor, hypotelorism, microcephaly, or other craniofacial findings that can be present with or without associated brain malformations. The aetiology of HPE is extremely heterogeneous, with the proposed participation of a minimum of 12 HPE-associated genetic loci as well as the causal involvement of specific teratogens acting at the earliest stages of neurulation. The HPE2 locus was recently characterized as a 1-Mb interval on human chromosome 2p21 that contained a gene associated with HPE. A minimal critical region was defined by a set of six overlapping deletions and three clustered translocations in HPE patients. We describe here the isolation and characterization of the human homeobox-containing SIX3 gene from the HPE2 minimal critical region (MCR). We show that at least 2 of the HPE-associated translocation breakpoints in 2p21 are less than 200 kb from the 5' end of SIX3. Mutational analysis has identified four different mutations in the homeodomain of SIX3 that are predicted to interfere with transcriptional activation and are associated with HPE. We propose that SIX3 is the HPE2 gene, essential for the development of the anterior neural plate and eye in humans.

Mutations in a new gene, encoding a zinc-finger protein, cause tricho-rhino-phalangeal syndrome type I.

Tricho-rhino-phalangeal syndrome type I (TRPS I, MIM 190350) is a malformation syndrome characterized by craniofacial and skeletal abnormalities and is inherited in an autosomal dominant manner. TRPS I patients have sparse scalp hair, a bulbous tip of the nose, a long flat philtrum, a thin upper vermilion border and protruding ears. Skeletal abnormalities include cone-shaped epiphyses at the phalanges, hip malformations and short stature. We assigned TRPS1 to human chromosome 8q24. It maps proximal of EXT1, which is affected in a subgroup of patients with multiple cartilaginous exostoses and deleted in all patients with TRPS type II (TRPS II, or Langer-Giedion syndrome, MIM 150230; ref.2-5). We have positionally cloned a gene that spans the chromosomal breakpoint of two patients with TRPS I and is deleted in five patients with TRPS I and an interstitial deletion. Northern-blot analyses revealed transcripts of 7 and 10.5 kb. TRPS1has seven exons and an ORF of 3,843 bp. The predicted protein sequence has two potential nuclear localization signals and an unusual combination of different zinc-finger motifs, including IKAROS-like and GATA-binding sequences. We identified six different nonsense mutations in ten unrelated patients. Our findings suggest that haploinsufficiency for this putative transcription factor causes TRPS I.

Microcephalic osteodysplastic primordial dwarfism type I with biallelic mutations in the RNU4ATAC gene.

Microcephalic osteodysplastic primordial dwarfism type I (MOPD I) is a rare autosomal recessive developmental disorder characterized by extreme intrauterine growth retardation, severe microcephaly, central nervous system abnormalities, dysmorphic facial features, skin abnormalities, skeletal changes, limb deformations, and early death. Recently, mutations in the RNU4ATAC gene, which encodes U4atac, a small nuclear RNA that is a crucial component of the minor spliceosome, were found to cause MOPD I. MOPD I is the first disease known to be associated with a defect in small nuclear RNAs. We describe here the clinical and molecular data for 17 cases of MOPD I, including 15 previously unreported cases, all carrying biallelic mutations in the RNU4ATAC gene.

Two novel germline KRAS mutations: expanding the molecular and clinical phenotype.

Noonan and Cardio-facio-cutaneous (CFC) syndromes are characterized by typical dysmorphic features, cardiac defects, short stature, variable ectodermal anomalies, and intellectual disability. Both belong to the Ras/mitogen-activated protein kinase pathway group of disorders and clinical features overlap other related conditions, notably LEOPARD and Costello syndromes. KRAS mutations account for about 2% of reported Noonan and <5% of reported CFC cases. The mutation spectrum includes recurrent missense changes clustering in particular domains of the KRAS protein and conferring gain-of-function. We report three patients from two unrelated families with novel missense KRAS mutations, p.K147E and p.Y71H. Both mutations affect a residue which is highly conserved in KRAS and other RAS isoforms. One of the families includes a mother and son pair who represent the first report of a vertically transmitted KRAS mutation. In addition, the mother and son pair had peripheral neuropathy, complicated by Charcot arthropathy in the mother. An unusual phenotypic effect of the specific KRAS mutation or a coincidence of two independent disorders may be considered. KRAS mutation-associated phenotypes appear to be subject to considerable clinical heterogeneity. All three cases highlight the challenges of clinical assessment in KRAS mutation-positive patients, and the utility of molecular testing as an adjunct to diagnosis.

[Glycogenosis type IV (Andersen disease). Clinical data, pathology, and genetics in a fatal perinatal case]. / Glykogenose Typ IV (Andersen). Klinik, Pathologie und Genetik eines letalen perinatalen Falles.

Here we report the case of a newborn with glycogenosis type IV (Andersen disease), who died shortly after birth. The diagnosis was established in the first instance by light microscopy and histochemistry, and subsequently ultrastructurally. DNA could be extracted from a fibroblast cell culture by sequencing the causative GBE1 gene (glycogen branching enzyme 1). Two compound heterozygous mutations in the gene were identified. The differential diagnosis should include Lafora disease as well as polyglucosan body disease. Since there is no effective therapy for glycogenosis type IV to date, prenatal diagnosis is mandatory.

Arterial tortuosity syndrome: clinical and molecular findings in 12 newly identified families.

Arterial tortuosity syndrome (ATS) is a rare autosomal recessive connective tissue disease, characterized by widespread arterial involvement with elongation, tortuosity, and aneurysms of the large and middle-sized arteries. Recently, SLC2A10 mutations were identified in this condition. This gene encodes the glucose transporter GLUT10 and was previously suggested as a candidate gene for diabetes mellitus type 2. A total of 12 newly identified ATS families with 16 affected individuals were clinically and molecularly characterized. In addition, extensive cardiovascular imaging and glucose tolerance tests were performed in both patients and heterozygous carriers. All 16 patients harbor biallelic SLC2A10 mutations of which nine are novel (six missense, three truncating mutations, including a large deletion). Haplotype analysis suggests founder effects for all five recurrent mutations. Remarkably, patients were significantly older than those previously reported in the literature (P=0.04). Only one affected relative died, most likely of an unrelated cause. Although the natural history of ATS in this series was less severe than previously reported, it does indicate a risk for ischemic events. Two patients initially presented with stroke, respectively at age 8 months and 23 years. Tortuosity of the aorta or large arteries was invariably present. Two adult probands (aged 23 and 35 years) had aortic root dilation, seven patients had localized arterial stenoses, and five had long stenotic stretches of the aorta. Heterozygous carriers did not show any vascular anomalies. Glucose metabolism was normal in six patients and eight heterozygous individuals of five families. As such, overt diabetes is not related to SLC2A10 mutations associated with ATS.

Defining the phenotype in an autosomal recessive cutis laxa syndrome with a combined congenital defect of glycosylation.

Autosomal recessive cutis laxa is a genetically heterogeneous condition. Its molecular basis is largely unknown. Recently, a combined disorder of N- and O-linked glycosylation was described in children with congenital cutis laxa in association with severe central nervous system involvement, brain migration defects, seizures and hearing loss. We report on seven additional patients with similar clinical features in combination with congenital disorder of glycosylation type IIx. On the basis of phenotype in 10 patients, we define an autosomal recessive cutis laxa syndrome. The patients have a complex phenotype of neonatal cutis laxa, transient feeding intolerance, late closure of the fontanel, characteristic facial features including down-slanting palpebral fissures, short nose and small mouth, and developmental delay. There is a variable degree of the central nervous system involvement and variable systemic presentation. The biochemical analysis using transferrin isoelectric focusing gives false negative results in some of the youngest patients. Analysis of the apolipoprotein C-III isoelectric focusing, however, is diagnostic in all cases.

Mutation and phenotypic spectrum in patients with cardio-facio-cutaneous and Costello syndrome.

Cardio-facio-cutaneous (CFC) and Costello syndrome (CS) are congenital disorders with a significant clinical overlap. The recent discovery of heterozygous mutations in genes encoding components of the RAS-RAF-MAPK pathway in both CFC and CS suggested a similar underlying pathogenesis of these two disorders. While CFC is heterogeneous with mutations in BRAF, MAP2K1, MAP2K2 and KRAS, HRAS alterations are almost exclusively associated with CS. We carried out a comprehensive mutation analysis in 51 CFC-affected patients and 31 individuals with CS. Twelve different BRAF alterations were found in twenty-four patients with CFC (47.0%), two MAP2K1 mutations in five (9.8%) and two MAP2K2 sequence variations in three CFC-affected individuals (5.9%), whereas three patients had a KRAS alteration (5.9%). We identified four different missense mutations of HRAS in twenty-eight cases with CS (90.3%), while KRAS mutations were detected in two infants with a phenotype meeting criteria for CS (6.5%). In 14 informative families, we traced the parental origin of HRAS alterations and demonstrated inheritance of the mutated allele exclusively from the father, further confirming a paternal bias in the parental origin of HRAS mutations in CS. Careful clinical evaluation of patients with BRAF and MAP2K1/2 alterations revealed the presence of slight phenotypic differences regarding craniofacial features in MAP2K1- and MAP2K2-mutation positive individuals, suggesting possible genotype-phenotype correlations.

Ataxia with oculomotor apraxia type 2: novel mutations in six patients with juvenile age of onset and elevated serum alpha-fetoprotein.

Ataxia with oculomotor apraxia type 2 (AOA2), a neurodegenerative disorder with juvenile to adolescent onset is caused by mutations within the SENATAXIN gene ( SETX). We performed molecular analyses in six patients showing clinically an AOA2 phenotype and moderate to significant elevated serum alpha-fetoprotein levels. Sequencing the 24 coding exons and flanking intronic sequences revealed 11 novel DNA variations, including seven unknown missense mutations, a dinucleotide deletion, a four-nucleotide deletion affecting the 5' splice site of exon 22 and two sequence variations, which are considered to be polymorphisms. By molecular testing the clinical diagnosis has been confirmed in all patients.

Screening of the SPTBN2 (SCA5) gene in German SCA patients.

The spinocerebellar ataxias (SCAs) with autosomal dominant inheritance are a clinically and genetically heterogeneous group of neurodegenerative disorders. To date 27 different loci have been identified for these conditions. Recently, two deletions as well as one missense mutation in the beta-III spectrin gene (STBN2) were identified causing SCA5. To evaluate the clinical relevance of these mutations, we screened 310 familial and sporadic patients with ataxia. While none of the individuals tested had evidence for one of the known SCA5 mutations, additional sequencing of the coding region for 22 unrelated patients revealed three novel missense exchanges at evolutionary conserved amino acid positions. Even though each variation marks a unique genotype in 250 alleles, a disease causing capacity can be excluded with high probability. These results reflect the challenges for molecular analyses in SCA5.

Recurrent Miscarriage: Diagnostic and Therapeutic Procedures. Guideline of the DGGG (S1-Level, AWMF Registry No. 015/050, December 2013).

Purpose: Official guideline coordinated and published by the German Society of Gynecology and Obstetrics (DGGG). Aim of the guideline was to standardize the diagnosis and treatment of patients with recurrent miscarriage (RM). Recommendations were proposed, based on the current national and international literature and the experience of the involved physicians. Consistent definitions, objective assessments and standardized therapy were applied. Methods: Members of the different involved societies developed a consensus in an informal process based on the current literature. The consensus was subsequently approved by the heads of the scientific societies. Recommendations: Recommendations for the diagnosis and treatment of patients with RM were compiled which took the importance of established risk factors such as chromosomal, anatomical, endocrine, hemostatic, psychological, infectious and immunological disorders into consideration.

Effect of the size of the deletion and clinical manifestation in Wolf-Hirschhorn syndrome: analysis of 13 patients with a de novo deletion.

We performed clinical, cytogenetic, and molecular analyses on 13 patients (8 females and 5 males, aged 6 months to 13 years) with Wolf-Hirschhorn syndrome due to de novo deletions of chromosome 4p. All patients presented with the typical facial gestalt, microcephaly, and profound mental retardation. Other clinical signs were low birth weight (10/13; 77%), postnatal short stature (8/12; 66%), muscular hypotonia (12/13; 92%), seizures (11/13; 85%), congenital heart defects (4/13; 31%), colobomata of iris (4/12; 33%), genital anomalies (4/13; 31%), deafness (3/13; 23%), and renal anomalies (3/13; 23%). The smallest deletion was a submicroscopic terminal deletion of nearly 2.5 Mb. The largest was a terminal deletion of nearly 30 Mb. Cleft lip/palate, preauricular pits/tags, and congenital heart defects were present only in patients with terminal deletions larger than 10 Mb. The deviations from mean birth weight, birth length, and postnatal head circumference correlated with the size of the deletion. Determining the parental origin of the deletion with microsatellite markers, the maternal allele was missing in three patients and the paternal allele in eight patients. Our observations support the existence of a partial genotype-phenotype correlation in Wolf-Hirschhorn syndrome.

Two novel mutations confirm FGD1 is responsible for the Aarskog syndrome.

The Aarskog syndrome or facio-genital dysplasia (FGDY, MIM No. 305400) is an X-linked condition characterized by short stature, macrocephaly, facial, genital and skeletal anomalies. It is caused by mutation of the FGD1 gene mapped to the Xp11.21 region. To date, only one point mutation has been reported in an affected family, consisting of the insertion of an additional guanine residue at nucleotide 2122 of exon 7, which causes premature translational termination. We now report the finding of two novel FGD1 mutations, a missense mutation in a family of Italian origin and a deletion of 3 exons in a sporadic case from Germany. These mutations confirm the role of FGD1 as the gene responsible for the Aarskog syndrome.

A previously unrecognised phenotype characterised by obesity, muscular hypotonia, and ability to speak in patients with Angelman syndrome caused by an imprinting defect.

The clinical features of Angelman syndrome (AS) comprise severe mental retardation, postnatal microcephaly, macrostomia and prognathia, absence of speech, ataxia, and a happy disposition. We report on seven patients who lack most of these features, but presented with obesity, muscular hypotonia and mild mental retardation. Based on the latter findings, the patients were initially suspected of having Prader-Willi syndrome. DNA methylation analysis of SNRPN and D15S63, however, revealed an AS pattern, ie the maternal band was faint or absent. Cytogenetic studies and microsatellite analysis demonstrated apparently normal chromosomes 15 of biparental inheritance. We conclude that these patients have an imprinting defect and a previously unrecognised form of AS. The mild phenotype may be explained by an incomplete imprinting defect or by cellular mosaicism.

Comprehensive methylation analysis in typical and atypical PWS and AS patients with normal biparental chromosomes 15.

Imprinting defects in 15q11-q13 are a rare but significant cause of Prader-Willi syndrome (PWS) and Angelman syndrome (AS). Patients with an imprinting defect have apparently normal chromosomes 15 of biparental origin, but are recognised by @parental DNA methylation at D15S63 (PW71) or SNURF-SNRPN exon 1. We have investigated the methylation status of five additional loci in 12 such patients with or without a deletion in the imprinting centre. In each patient, the imprinting defect affected all loci tested. During routine diagnostic testing we identified four patients who had a normal methylation pattern at SNURF-SNRPN exon 1, but an abnormal pattern at D15S63. In two of these patients, who were suspected of having PWS, this change was restricted to D15S63. In two patients suspected of having AS, several but not all loci were affected. Using a newly developed methylation-specific PCR test for D15S63 we found that these methylation changes are rare in patients suspected of having AS. Although we can not prove that the methylation changes in the four patients are causally related to their disease, our findings demonstrate that spatially restricted changes in methylation can occur. In some cases, these changes may reflect incomplete imprint spreading.

Frequency gradients of DHCR7 mutations in patients with Smith-Lemli-Opitz syndrome in Europe: evidence for different origins of common mutations.

Smith-Lemli-Opitz syndrome/RSH (SLOS) is a multiple congenital anomaly syndrome caused by mutations in the gene for Delta7-sterol reductase (DHCR7) which catalyses the last step in the biosynthesis of cholesterol. SLOS is among the common recessive disorders in Europeans but almost absent in most other populations. More than 40 mutations in the DHCR7 gene some of which are frequent have been described in SLOS patients of various origins. Here we report mutation analysis of the DHCR7 gene in SLOS patients from Poland (n = 15), Germany/Austria (n = 22) and Great Britain (n = 22). Altogether 35 different mutations were identified and the two null mutations IVS8-1G > C and W151X were the most frequent in the total sample. In all three populations three mutations accounted for >0.5 of SLOS chromosomes. The mutational spectra were, however, significantly different across these populations with each of the common mutations showing an east-west gradient (W151X, V326L) or vice versa (IVS8-1G > C). W151X is the most frequent (0.33) mutation in Polish SLOS patients. It has an intermediate frequency in German/Austrian patients (0.18) and is rare among British patients (0.02). V326L shows the same distribution pattern (Poland 0.23, Germany/Austria 0.18, Britain 0.02). In contrast IVS8-1G > C is most frequent in Britain (0.34) intermediate in Germany/Austria (0.20) and rare in Poland (0.03). All analysed IVS8-1G > C and V326L alleles shared the same DHCR7 haplotype, whereas the W151X mutation occurred on different haplotypes. There is evidence for both recurrent mutations and founder effects. Together this suggests that the common SLOS mutations in Europe have different geographic and historic origins and spread across the continent in opposite directions.