The importance of genetic susceptibility in Dupuytren's disease.

Dupuytren's disease (DD) is a progressive fibromatosis that causes the formation of nodules and cords in the palmar aponeurosis leading to flexion contracture of affected fingers. The etiopathogenesis is multifactorial with a strong genetic predisposition. It is the most frequent genetic disorder of connective tissues. We have collected clinical data from 736 unrelated individuals with DD who underwent surgical treatment from Germany and Switzerland. We evaluated a standardised questionnaire, assessed the importance of different risk factors and compared subgroups with and without positive family history. We found that family history clearly had the strongest influence on the age at first surgery compared to environmental factors, followed by male sex. Participants with a positive family history were on average 55.9 years of age at the first surgical intervention, 5.2 years younger than probands without known family history (p = 6.7 × 10(-8) ). The percentage of familial cases decreased with age of onset from 55% in the 40-49 years old to 17% at age 80 years or older. Further risk factors analysed were cigarettes, alcohol, diabetes, hypertension, and epilepsy. Our data pinpoint the importance of genetic susceptibility for DD, which has long been underestimated.

Macrocephaly, obesity, mental (intellectual) disability, and ocular abnormalities: alternative definition and further delineation of MOMO syndrome.

MOMO syndrome, previously defined as Macrosomia, Obesity, Macrocephaly, and Ocular abnormalities (OMIM 157980) is a rare intellectual disability syndrome of unknown cause. We describe two further patients with MOMO syndrome. Reported data of patients with MOMO syndrome and our own findings indicate that overgrowth does not appear to be a specific feature. We propose to form the acronym "MOMO" from Macrocephaly, Obesity, Mental (intellectual) disability, and Ocular abnormalities, excluding macrosomia from the syndrome name. The combination of obesity, macrocephaly, and colobomas is unique, therefore these features can be used as major diagnostic criteria of MOMO syndrome.

A new autosomal dominant syndrome of distinctive face showing ptosis and prominent eyes associated with cleft palate, ear anomalies, and learning disability.

We report on three patients from two families with apparently a novel clinical entity. The main features of which include unusual craniofacial dysmorphism with ptosis, prominent eyes, flat midface, Cupid's bow configuration of the upper lip, low-set, posteriorly rotated small ears, as well as conductive hearing loss, cleft palate, heart defect, and mild developmental delay. We suggest that this entity is an autosomal dominant disorder given the occurrence in a mother and daughter as well as in an unrelated boy.

Hallermann-Streiff Syndrome: No Evidence for a Link to Laminopathies.

Hallermann-Streiff syndrome (HSS) is a rare inherited disorder characterized by malformations of the cranium and facial bones, congenital cataracts, microphthalmia, skin atrophy, hypotrichosis, proportionate short stature, teeth abnormalities, and a typical facial appearance with prominent forehead, small pointed nose, and micrognathia. The genetic cause of this developmental disorder is presently unknown. Here we describe 8 new patients with a phenotype of HSS. Individuals with HSS present with clinical features overlapping with some progeroid syndromes that belong to the laminopathies, such as Hutchinson-Gilford progeria syndrome (HGPS) and mandibuloacral dysplasia (MAD). HGPS is caused by de novo point mutations in the LMNA gene, coding for the nuclear lamina proteins lamin A and C. MAD with type A and B lipodystrophy are recessive disorders resulting from mutations in LMNA and ZMPSTE24, respectively. ZMPSTE24 in addition to ICMT encode proteins involved in posttranslational processing of lamin A. We hypothesized that HSS is an allelic disorder to HGPS and MAD. As the nuclear shape is often irregular in patients with LMNA mutations, we first analyzed the nuclear morphology in skin fibroblasts of patients with HSS, but could not identify any abnormality. Sequencing of the genes LMNA, ZMPSTE24 and ICMT in the 8 patients with HSS revealed the heterozygous missense mutation c.1930C>T (p.R644C) in LMNA in 1 female. Extreme phenotypic diversity and low penetrance have been associated with the p.R644C mutation. In ZMPSTE24 and ICMT, no pathogenic sequence change was detected in patients with HSS. Together, we found no evidence that HSS is another laminopathy.

Pontine tegmental cap dysplasia: the severe end of the clinical spectrum.

Pontine tegmental cap dysplasia (PTCD) is a newly described hindbrain malformation with distinct neuroradiological findings. Only 12 cases of PTCD have been described so far, all sporadic. We report 2 further patients. Both children presented after birth with significant feeding problems due to impaired mouth opening (previously not reported) and sucking difficulties. Facial, cochlear, and glossopharyngeal nerves were involved resulting in bilateral sensory deafness and a significant swallowing disorder requiring a gastrostomy. In one patient the trigeminal sensory nerve was also involved causing severe bilateral corneal clouding with impaired vision. Both patients showed only minimal developmental progress since birth and had no speech production. Furthermore, they had vertebral and rib anomalies. The patients died at the age of 15 and 32 months, respectively, due to intercurrent infections. The majority of patients reported previously were affected less severely. The presented patients may represent the severe end of the spectrum.

Three-generational alkaptonuria in a non-consanguineous family.

OBJECTIVE: Alkaptonuria (AKU) is a rare inborn error of metabolism of aromatic amino acids and considered to be an autosomal recessive trait caused by mutations in the homogentisate 1,2-dioxygenase (HGD) gene. A dominant pattern of inheritance has been reported but was attributed to extended consanguinity in many cases. However, we have observed a non-consanguineous family segregating AKU in a dominant manner over three generations. RESULTS: All affected individuals presented with typical features of AKU including darkening of the urine, ochronosis, arthropathy, and elevated urinary excretion of homogentisic acid. Sequence analysis of the HGD gene from genomic DNA of two affected individuals, uncle and niece, revealed a heterozygous missense mutation (M368V) in the uncle that was not present in his niece. Microsatellite genotyping demonstrated that both were heterozygous at the HGD locus and shared one haplotype. This haplotype did not contain a detectable HGD mutation. The haplotype was also found in a healthy son of the niece, making a dominant HGD mutation unlikely. Moreover, sequencing of cDNA from lymphoblastoid cells of the niece did not reveal an HGD mRNA with a potentially dominant-negative effect. CONCLUSION: Rare causes of the uncommon AKU inheritance in this family have to be considered, ranging from the coincidence of undetectable HGD mutations to a dominant mutation of a second, hitherto unknown AKU gene.

Stages of sleep pathology in spinocerebellar ataxia type 2 (SCA2).

BACKGROUND: Autosomal dominant spinocerebellar ataxia type 2 (SCA2) bears clinical and neuropathologic similarities to sporadic multisystem atrophy (MSA) or Parkinson disease, in which sleep pathology is well documented. However, those clinical entities have a marked variability of the reported sleep disturbances, and their etiology is heterogeneous. In contrast, the study of SCA2 provides an opportunity to examine a molecularly homogeneous patient group, in which disease stages can be defined not only based on disease duration and ataxia scores, but also with regard to modulatory effects of mutation size. OBJECTIVE: To examine the presence and progression of sleep pathology in SCA2. METHODS: We analyzed eight patients with disease durations of 3 to 31 years, all with medium size SCA2 expansions (CAG 38 to 49), using clinical scores, sleep interviews, and video-polysomnography (VPSG) recordings. RESULTS: Almost all patients reported good subjective sleep quality and negated incidents of REM behavior disorder (RBD). At early disease stages, however, REM without atonia in four patients' VPSG suggested subclinical RBD. This was accompanied by a consistent reduction of REM density. In three patients at later SCA2 stages, REM sleep was undetectable, whereas slow wave sleep (SWS) was markedly increased at the cost of light sleep. Periodic leg movements, apnea, or hypopnea were not prominent. CONCLUSIONS: Progressive loss of dream recall in spinocerebellar ataxia type 2 was found and correlated with stages of REM more than non-REM pathology in video-polysomnography. These stages correspond to the progressive atrophy from the pons, nigrostriatal projection, and locus ceruleus to the thalamus.

Towards characterization of palmoplantar keratoderma caused by gain-of-function mutation in loricrin: analysis of a family and review of the literature.

Loricrin keratoderma is an autosomal dominant palmoplantar keratoderma heterogeneous in clinical appearance. We report a family with diffuse ichthyosis and honeycomb palmoplantar keratoderma but no occurrence of pseudoainhums or autoamputations. All patients were born as collodion babies and displayed prominent knuckle pads. We identified the previously reported mutation 730insG in LOR, which elongates loricrin by 22 amino acids because of delayed termination. As pseudoainhums are missing in all patients of the family reported, we propose two compulsory features of loricrin keratoderma: (i) honeycomb palmoplantar keratoderma and (ii) diffuse ichthyosiform dermatosis. Therefore we suggest that the condition should be described clinically as 'honeycomb palmoplantar keratoderma with ichthyosis'. Furthermore, we have assessed the amounts of transcript of LOR using pyrosequencing. This revealed an equal expression of mutant and wild-type alleles of LOR in an affected individual. These findings further underline the gain-of-function theory for mutant LOR in loricrin keratoderma.

Spectrum of single- and multiexon NF1 copy number changes in a cohort of 1,100 unselected NF1 patients.

Neurofibromatosis type 1 (NF1), the most common tumor-predisposing disorder in humans, is caused by defects in the NF1 tumor-suppressor gene. Comprehensive mutation analysis applying RNA-based techniques complemented with FISH analysis achieves mutation detection rates of approximately 95% in NF1 patients. The majority of mutations are minor lesions, and approximately 5% are total gene deletions. We found 13 single- and/or multiexon deletions/duplications out of 1,050 detected mutations using our RNA-based approach in a cohort of 1,100 NF1 patients and confirmed these changes using multiplex ligation-dependent probe amplification (MLPA). With MLPA, we found another 12 novel multiexon deletion/duplications in 55 NF1 patients for whom analysis with multiple assays had not revealed a NF1 mutation, including 50 previously analyzed comprehensively. The extent of the 22 deletions and 3 duplications varied greatly, and there was no clustering of breakpoints. We also evaluated the sensitivity of MLPA in identifying deletions in a mosaic state. Furthermore, we tested whether the MLPA P122 NF1 area assay could distinguish between type I deletions, with breakpoints in low-copy repeats (NF1-LCRs), and type II deletions, caused by aberrant recombination between the JJAZ gene and its pseudogene. Our study showed that intragenic deletions and/or duplications represent only approximately 2% of all NF1 mutations. Although MLPA did not substantially increase the mutation detection rate in NF1 patients, it was a useful first step in a comprehensive mutation analysis scheme to quickly pinpoint patients with single- or multiexon deletions/duplications as well as patients with a total gene deletion who will not need full sequencing of the complete coding region.

The Kabuki syndrome: four patients with oral abnormalities.

The aim of this paper is to report the oral signs and symptoms of four patients with Kabuki syndrome. All had oral abnormalities affecting the palate, teeth, and/or lips, including wide spacing between the teeth, screwdriver-shaped upper incisors, hypodontia, delayed tooth eruption, narrow spacing in the upper canine area, large pulp chambers of the upper incisors and permanent molars, external root resorption of the upper central incisors and permanent molars, a division of the lower third of the root canal in normally one-rooted teeth, tooth retention, retrognathia of the upper jaw, a high palate or cleft lip/palate, and microforms of lower lip fistula.

Is the distribution of dermal neurofibromas in neurofibromatosis type 1 (NF1) related to the pattern of the skin surface temperature?

The formation of dermal neurofibromas is a hallmark of the neurofibromatosis type 1 (NF1). A total loss of the NF1 gene product by stochastic events inactivating the wild type allele in Schwann cells should precede the development of neurofibromas. Dermal neurofibromas tend to be located mainly on the surface of the trunk and not in the body periphery. This distribution partly resembles the density of sensitive nerve endings in the epidermis. Our hypothesis is that a better correlation concerns the pattern of normal body surface temperature. According to our clinical observations we assume that in skin areas with higher temperatures the number of visible dermal neurofibromas is higher than in colder areas such as the arms/legs or nose. It is known that differences in temperature are able to determine differentiation. We suggest that the regulation of skin temperature is also involved in the formation of NF1 dermal neurofibromas and is related to the intrafamilial variability in NF1.

Molecular characterization and gene content of breakpoint boundaries in patients with neurofibromatosis type 1 with 17q11.2 microdeletions.

Homologous recombination between poorly characterized regions flanking the NF1 locus causes the constitutional loss of approximately 1.5 Mb from 17q11.2 covering > or =11 genes in 5%-20% of patients with neurofibromatosis type 1 (NF1). To elucidate the extent of microheterogeneity at the deletion boundaries, we used single-copy DNA fragments from the extreme ends of the deleted segment to perform FISH on metaphase chromosomes from eight patients with NF1 who had large deletions. In six patients, these probes were deleted, suggesting that breakage and fusions occurred within the adjacent highly homologous sequences. Reexamination of the deleted region revealed two novel functional genes FLJ12735 (AK022797) and KIAA0653-related (WI-12393 and AJ314647), the latter of which is located closest to the distal boundary and is partially duplicated. We defined the complete reading frames for these genes and two expressed-sequence tag (EST) clusters that were reported elsewhere and are associated with the markers SHGC-2390 and WI-9521. Hybrid cell lines carrying only the deleted chromosome 17 were generated from two patients and used to identify the fusion sequences by junction-specific PCRs. The proximal breakpoints were found between positions 125279 and 125479 in one patient and within 4 kb of position 143000 on BAC R-271K11 (AC005562) in three patients, and the distal breakpoints were found at the precise homologous position on R-640N20 (AC023278). The interstitial 17q11.2 microdeletion arises from unequal crossover between two highly homologous WI-12393-derived 60-kb duplicons separated by approximately 1.5 Mb. Since patients with the NF1 large-deletion syndrome have a significantly increased risk of neurofibroma development and mental retardation, hemizygosity for genes from the deleted region around the neurofibromin locus (CYTOR4, FLJ12735, FLJ22729, HSA272195 (centaurin-alpha2), NF1, OMGP, EVI2A, EVI2B, WI-9521, HSA272196, HCA66, KIAA0160, and WI-12393) may contribute to the severe phenotype of these patients.

Refinement of the chromosome 5p locus for craniometaphyseal dysplasia.

Craniometaphyseal dysplasia--Jackson type (CMDJ) is an autosomal dominant bone dysplasia with hyperostosis and sclerosis of the skull and abnormal modelling of the metaphyses. In a large German pedigree, a locus for CMDJ has been mapped previously to the short arm of chromosome 5 (5p15.2-p14.1), defining a 19-cM disease interval between markers D5S2004 and D5S502. Analysis of a large Australian pedigree together with a second German family confirms linkage to the same region. Obligate recombinations in the new families and confirmation of a supposed recombination in the previously reported German kindred have enabled us to narrow the critical region down to approximately 4 cM between markers D5S1987 and D5S1991.

Metaphyseal dysplasia: a new autosomal dominant type in a large German kindred.

We describe a new autosomal dominant type of metaphyseal dysplasia (MD) in five generations of a German kindred. The main characteristics are metaphyseal widening and undermodeling of the tubular bones with Erlenmeyer flask-like appearance of the distal femora (typical of MD), with unusually severe varus deformity of the radii and flat exostoses of the long bones localized in the metaphyses. The skull is unaffected. Allelism with craniometaphyseal dysplasia (CMD) was excluded by linkage analysis.

Heterozygous mutations in ANKH, the human ortholog of the mouse progressive ankylosis gene, result in craniometaphyseal dysplasia.

Craniometaphyseal dysplasia (CMD) is a bone dysplasia characterized by overgrowth and sclerosis of the craniofacial bones and abnormal modeling of the metaphyses of the tubular bones. Hyperostosis and sclerosis of the skull may lead to cranial nerve compressions resulting in hearing loss and facial palsy. An autosomal dominant form of the disorder (MIM 123000) was linked to chromosome 5p15.2-p14.1 (ref. 3) within a region harboring the human homolog (ANKH) of the mouse progressive ankylosis (ank) gene. The ANK protein spans the outer cell membrane and shuttles inorganic pyrophosphate (PPi), a major inhibitor of physiologic and pathologic calcification, bone mineralization and bone resorption. Here we carry out mutation analysis of ANKH, revealing six different mutations in eight of nine families. The mutations predict single amino acid substitutions, deletions or insertions. Using a helix prediction program, we propose for the ANK molecule 12 membrane-spanning helices with an alternate inside/out orientation and a central channel permitting the passage of PPi. The mutations occur at highly conserved amino acid residues presumed to be located in the cytosolic portion of the protein. Our results link the PPi channel ANK with bone formation and remodeling.

[Variable expression of lower lip fistulas in Van der Woude syndrome]. / Variable Ausprägung der Unterlippenfisteln beim Van-der-Woude-Syndrom.

Eight families with the combination of cleft lip and/or cleft palate plus lower lip pits including their microforms were examined with the aim of characterization of microsymptoms. Hypodontia as a further symptom was also taken into consideration. Each of the symptoms was also noted separately in relatives of the patients and are to be considered as a genetic equivalent of the complete form of the autosomal-dominant inherited Van der Woude's syndrome. Knowledge of the variable expression of the basic gene is crucial for risk assessment in family counselling and also for distinguishing from clefts of other genesis with lower recurrence risk.

Distinct mutations in the receptor tyrosine kinase gene ROR2 cause brachydactyly type B.

Brachydactyly type B (BDB) is an autosomal dominant skeletal disorder characterized by hypoplasia/aplasia of distal phalanges and nails. Recently, heterozygous mutations of the orphan receptor tyrosine kinase (TK) ROR2, located within a distinct segment directly after the TK domain, have been shown to be responsible for BDB. We report four novel mutations in ROR2 (two frameshifts, one splice mutation, and one nonsense mutation) in five families with BDB. The mutations predict truncation of the protein within two distinct regions immediately before and after the TK domain, resulting in a complete or partial loss of the intracellular portion of the protein. Patients affected with the distal mutations have a more severe phenotype than do those with the proximal mutation. Our analysis includes the first description of homozygous BDB in an individual with a 5-bp deletion proximal to the TK domain. His phenotype resembles an extreme form of brachydactyly, with extensive hypoplasia of the phalanges and metacarpals/metatarsals and absence of nails. In addition, he has vertebral anomalies, brachymelia of the arms, and a ventricular septal defect-features that are reminiscent of Robinow syndrome, which has also been shown to be caused by mutations in ROR2. The BDB phenotype, as well as the location and the nature of the BDB mutations, suggests a specific mutational effect that cannot be explained by simple haploinsufficiency and that is distinct from that in Robinow syndrome.