At first sight or second glance: clinical presentation of mosaic manifestations of autosomal dominant skin disorders - a case series.

BACKGROUND: Several autosomal dominant disorders may manifest in mosaic patterns with cutaneous involvement. Genomic mosaicism results from postzygotic autosomal mutations, giving rise to clonal proliferation of two genetically distinct cell groups, which clinically present as lesions following the lines of Blaschko. OBJECTIVE: To increase the awareness of the clinical variability of mosaic manifestations in autosomal dominant skin disorders in order to avoid delayed diagnosis. METHODS: Clinicopathologic correlation in a case series including three patients with mosaic manifestations of different autosomal dominant skin diseases. RESULTS: Here, we describe a patient with type 1 segmental mosaicism of epidermolytic ichthyosis (case 1) and two patients with either type 1 (case 2) or type 2 (case 3) segmental neurofibromatosis 1 (NF1). CONCLUSION: Dermatologists should be familiar with mosaic manifestations of autosomal dominant skin diseases to ensure appropriate guidance of the affected patient. Genetic counselling is mandatory as even limited forms of mosaicism may involve the patient's germline with a moderately increased risk to transmit the mutation to their offspring, resulting in a more severe, generalized form of the respective disease.

Clinical reappraisal of SHORT syndrome with PIK3R1 mutations: toward recommendation for molecular testing and management.

SHORT syndrome has historically been defined by its acronym: short stature (S), hyperextensibility of joints and/or inguinal hernia (H), ocular depression (O), Rieger abnormality (R) and teething delay (T). More recently several research groups have identified PIK3R1 mutations as responsible for SHORT syndrome. Knowledge of the molecular etiology of SHORT syndrome has permitted a reassessment of the clinical phenotype. The detailed phenotypes of 32 individuals with SHORT syndrome and PIK3R1 mutation, including eight newly ascertained individuals, were studied to fully define the syndrome and the indications for PIK3R1 testing. The major features described in the SHORT acronym were not universally seen and only half (52%) had four or more of the classic features. The commonly observed clinical features of SHORT syndrome seen in the cohort included intrauterine growth restriction (IUGR) <10th percentile, postnatal growth restriction, lipoatrophy and the characteristic facial gestalt. Anterior chamber defects and insulin resistance or diabetes were also observed but were not as prevalent. The less specific, or minor features of SHORT syndrome include teething delay, thin wrinkled skin, speech delay, sensorineural deafness, hyperextensibility of joints and inguinal hernia. Given the high risk of diabetes mellitus, regular monitoring of glucose metabolism is warranted. An echocardiogram, ophthalmological and hearing assessments are also recommended.

Loss of function of PGAP1 as a cause of severe encephalopathy identified by Whole Exome Sequencing: Lessons of the bioinformatics pipeline.

We evaluated a multiple consanguineous Turkish family with two children, a boy and a girl, affected by severe encephalopathy, hypotonia, microcephaly and retinal dystrophy by a combination of linkage analysis and Whole Exome Sequencing (WES). We analyzed the sequence data by two different bioinformatics pipelines which did not differ in overall processing strategy but involved differences in software used, minor allele frequency (MAF) thresholds and reference data sets, the usage of in-house control exomes and filter settings to prioritize called variants. Assuming autosomal recessive mode of inheritance, only homozygous variants present in both children were considered. The resulting variant lists differed partially (nine variants identified by both pipelines, ten variants by only one pipeline). Major reasons for this discrepancy were different filters for MAF and different variant prioritizations. Combining the variant lists with the results of linkage analysis and further prioritization by expression data and prediction tools, an intronic homozygous splice variant (c.1090-2A>G; IVS9-2A>G; p.?) in PGAP1 (Post-GPI Attachment To Proteins 1) was identified and validated by cDNA analysis. PGAP1 ensures the first step of maturation of GPI (glycosylphosphatidylinositol)-anchor proteins. Recently, a homozygous loss-of-function mutation in PGAP1 has been reported in one family with two children affected by a similar phenotype. The present report not only illustrates the possible influence of specific filtering settings on the results of WES but also confirms PGAP1 as a cause of severe encephalopathy.

Craniofrontonasal syndrome in a male due to chromosomal mosaicism involving EFNB1: further insights into a genetic paradox.

Craniofrontonasal syndrome (CFNS) is an X-linked disorder caused by inactivating mutations in the gene for ephrin-B1 (EFNB1). Paradoxically it shows a more severe phenotype in females than in males. As a result of X inactivation cell populations with and without EFNB1 expression are found in EFNB1+/- females. This is thought to initiate a process termed cellular interference which may be responsible for the phenotype in females. We present a boy with severe clinical features of CFNS. In ∼42% of his blood cells we found a supernumerary ring X chromosome containing EFNB1 but lacking XIST. Mosaicism for cell populations with different levels of EFNB1 expression can explain the severe phenotype of this patient. In vitro experiments in Xenopus tissue showed that cells overexpress ephrinB1 cluster and sort out from wild-type cells. Our report provides further evidence that cellular interference contributes to the paradoxical inheritance pattern of CFNS.

PIK3R1 mutations in SHORT syndrome.

SHORT syndrome (OMIM 269880) is a rare autosomal-dominant disorder characterized by short stature, hyperextensibility of joints, hernias, ocular depression, ophthalmic anomalies (Rieger anomaly, posterior embryotoxon, glaucoma), teething delay, partial lipodystrophy, insulin resistance and facial dysmorphic signs. Heterozygous mutations in PIK3R1 were recently identified in 14 families with SHORT syndrome. Eight of these families had a recurrent missense mutation (c.1945C>T; p.Arg649Trp). We report on two unrelated patients with typical clinical features of SHORT syndrome and additional problems such as pulmonary stenosis and ectopic kidney. Analysis of PIK3R1 revealed the mutation c.1945C>T; p.Arg649Trp de novo in both patients. These two patients not only provide additional evidence that PIK3R1 mutations cause SHORT syndrome, but also broaden the clinical spectrum of this syndrome and further confirm that the amino acid exchange c.1945C>T; p.Arg649Trp is a hotspot mutation in this gene.

Deletion of MAP2K2/MEK2: a novel mechanism for a RASopathy?

RASopathies are a class of genetic syndromes caused by germline mutations in genes encoding Ras/mitogen-activated protein kinase (Ras/MAPK) pathway components. Cardio-facio-cutaneous (CFC) syndrome is a RASopathy characterized by distinctive craniofacial features, skin and hair abnormalities, and congenital heart defects caused by activating mutations of BRAF, MEK1, MEK2, and KRAS. We define the phenotype of seven patients with de novo deletions of chromosome 19p13.3 including MEK2; they present with a distinct phenotype but have overlapping features with CFC syndrome. Phenotypic features of all seven patients include tall forehead, thick nasal tip, underdeveloped cheekbones, long midface, sinuous upper vermilion border, tall chin, angular jaw, and facial asymmetry. Patients also have developmental delay, hypotonia, heart abnormalities, failure to thrive, obstructive sleep apnea, gastroesophageal reflux and integument abnormalities. Analysis of epidermal growth factor-stimulated fibroblasts revealed that P-MEK1/2 was ∼50% less abundant in cells carrying the MEK2 deletion compared to the control. Significant differences in total MEK2 and Sprouty1 abundance were also observed. Our cohort of seven individuals with MEK2 deletions has overlapping features associated with RASopathies. This is the first report suggesting that, in addition to activating mutations, MEK2 haploinsufficiency can lead to dysregulation of the MAPK pathway.

Silver-Russell syndrome due to maternal uniparental disomy 7 and a familial reciprocal translocation t(7;13).

Silver-Russell syndrome (SRS) is a genetically heterogeneous disorder characterized by intrauterine and postnatal growth retardation, typical facial features and a spectrum of additional features including body and limb asymmetry and clinodactyly. Maternal uniparental disomy for chromosome 7 (upd(7)mat) was shown to occur in 5-10% of patients with SRS. Maternal UPD7 is clinically often associated with mild SRS. Parents of an affected child are given a negligible recurrence risk as all reported cases with upd(7)mat have been sporadic so far. In general, chromosomal rearrangements-like translocations increase the likelihood of uniparental disomy (UPD) for the chromosomes involved. However, SRS as the result of a upd(7)mat in association with an inherited chromosomal translocation involving chromosome 7 has only been reported once before. Here, we describe the second case of SRS with upd(7)mat due to a familial reciprocal translocation t(7;13). This emphasizes the importance of chromosome analysis in SRS patients with upd(7)mat to rule out chromosomal rearrangements despite their rare occurrence as they are of great relevance for genetic counseling of SRS families.

Pseudoautosomal inheritance of Léri-Weill syndrome: what does it mean?

The short stature homeobox (SHOX) gene is located in the pseudoautosomal region 1 of both sex chromosomes. Haploinsufficiency of SHOX leads to different phenotypes ranging from isolated short stature to Léri-Weill syndrome characterized by short stature, mesomelia and Madelung deformity. We describe a family with a SHOX deletion originally located on the Y chromosome and transmitted from father to daughter by crossover during meiosis. The male index patient presented with short stature, mesomelia and mild Madelung deformity. His father had a normal height but slightly disproportionate short legs. The sister of the index patient presented with marked Madelung deformity and normal height. A deletion of the SHOX gene was identified in the male index patient, his father and his sister. Metaphase fluorescence in situ hybridization (FISH) analyses showed a deletion of the SHOX gene on the Y chromosomes of the index patient and his father, and on the X chromosome of his sister, indicating that a meiotic crossover of the SHOX gene region between the X and Y chromosomes had occurred. The pseudoautosomal region 1 is a known recombination 'hot spot' in male meiosis. Published genetic maps indicate high recombination frequency of ∼40% for SHOX in male meiosis leading to pseudoautosomal inheritance.

Encephalocraniocutaneous lipomatosis.

BACKGROUND: Encephalocraniocutaneous lipomatosis (ECCL) is a sporadically occurring neurocutaneous disorder of unknown aetiology. It has repeatedly been discussed as a localised form of Proteus syndrome. In 2006, the first large series of patients was reported, and diagnostic criteria were proposed. AIMS: To better define the phenotypic spectrum and natural history of ECCL and to revise diagnostic criteria. METHODS: 54 patients with ECCL were reviewed. RESULTS: Eye anomalies (mainly choristomas) and skin lesions (non-scarring alopecia, naevus psiloliparus, subcutaneous fatty masses, nodular skin tags, aplastic scalp defects) may be unilateral or bilateral and occur in a consistent pattern. Central nervous system anomalies consist of intracranial and intraspinal lipomas, congenital abnormalities of the meninges, and putative focal vascular defects resulting in highly asymmetrical changes. About two-thirds of patients have a normal development or mild retardation only, and half of them have seizures. No correlation between the extent of central nervous system anomalies and neurological features could be established. Aortic coarctation, progressive bone cysts and jaw tumours may be associated. CONCLUSIONS: Revised diagnostic criteria are proposed. ECCL is considered to differ from Proteus syndrome in particular, but oculoectodermal syndrome is possibly a mild variant. Pathogenetically, mosaicism for a mutated autosomal gene involved in multiple mesenchymal tumours and vasculogenesis, with or without a second hit event, is discussed.

Mental retardation and inborn errors of metabolism.

In countries where clinical phenylketonuria is detected by newborn screening inborn errors of metabolism are rare causes of isolated mental retardation. There is no international agreement about what type of metabolic tests must be applied in patients with unspecific mental retardation. However, and although infrequent, there are a number of inborn errors of metabolism that can present in this way. Because of the high recurrence risk and the possibility of specific therapies, guidelines need to be developed and adapted to different populations. The application of a universal protocol may result in a low diagnostic performance in individual ethnic populations. Consideration of associated signs (extraneurological manifestations, psychiatric signs, autistic traits, cerebellar dysfunction, epilepsy or dysmorphic traits) greatly improves the diagnostic fulfilment.

Oculodentodigital Dysplasia: A Hypomyelinating Leukodystrophy with a Characteristic MRI Pattern of Brain Stem Involvement.

Oculodentodigital dysplasia, a rare genetic disorder caused by mutations in the gene encoding gap junction protein 1, classically presents with typical facial features, dental and ocular anomalies, and syndactyly. Oligosymptomatic patients are common and difficult to recognize, in particular if syndactyly is absent. Neurologic manifestation occurs in approximately 30% of patients, and leukodystrophy or T2 hypointensity of gray matter structures or both have been noted in individual patients. To investigate MR imaging changes in oculodentodigital dysplasia, we retrospectively and systematically reviewed 12 MRIs from 6 genetically confirmed patients. Diffuse supratentorial hypomyelination, T2-hypointense Rolandic and primary visual cortex, and symmetric involvement of middle cerebellar peduncle, pyramidal tract, and medial lemniscus was present in all, T2-hypointense pallidum and dentate nucleus in 2 patients each. This consistent, characteristic pattern of diffuse supratentorial hypomyelination and brain stem involvement differs from other hypomyelinating and nonhypomyelinating leukodystrophies with brain stem involvement, and its recognition should trigger genetic testing for oculodentodigital dysplasia.

Oculocerebrocutaneous syndrome: the brain malformation defines a core phenotype.

BACKGROUND: Oculocerebrocutaneous syndrome (OCCS) is characterised by orbital cysts and anophthalmia or microphthalmia, focal aplastic or hypoplastic skin defects, skin appendages, and brain malformations. The eye and skin abnormalities are well described but the neuropathological features less so. To date, 28 patients with an unequivocal diagnosis of OCCS have been reported, with a preponderance of males. OBJECTIVE: To evaluate the brain imaging studies, clinical records, photographs, and pathological material of two new and nine previously reported cases of OCCS. RESULTS: There was a consistent pattern of malformations in eight of the 11 cases, consisting of frontal predominant polymicrogyria and periventricular nodular heterotopia, enlarged lateral ventricles or hydrocephalus, agenesis of the corpus callosum sometimes associated with interhemispheric cysts, and a novel mid-hindbrain malformation. The latter consisted of a giant and dysplastic tectum, absent cerebellar vermis, small cerebellar hemispheres in most cases, and a large posterior fossa fluid collection. CONCLUSIONS: The mid-hindbrain malformation appears pathognomonic for OCCS. The eye and skin features of OCCS show considerable overlap with several other syndromes, such as encephalocraniocutaneous lipomatosis, oculo-auriculo-vertebral spectrum, and focal dermal hypoplasia, none of which has a comparable pattern of brain malformations. In particular the unique mid-hindbrain malformation also distinguishes OCCS from related syndromes with comparable forebrain anomalies. The pattern of malformation described thus helps in differentiating OCCS from other entities. The mid-hindbrain malformation points to a defect of the mid-hindbrain organiser as the underlying pathogenic mechanism.

Randomized trial of a shared decision-making intervention consisting of trade-offs and individualized treatment information for BRCA1/2 mutation carriers.

PURPOSE: To evaluate a shared decision-making intervention (SDMI) for BRCA1/2 mutation carriers who have to make a choice between screening and prophylactic surgery for breasts and/or ovaries. PATIENTS AND METHODS: The SDMI consisted of two value assessment sessions, using the time trade-off method, followed by individualized treatment information based on (quality-adjusted) life expectancy. After the baseline assessment (2 weeks after a positive DNA test result), women were randomly assigned to the SDMI group (n = 44), receiving the SDMI 2 months after the test result, or to the control group (n = 44). The short- and long-term effects, 3 and 9 months after the test result, were assessed using questionnaires. Data were collected on well-being, treatment choice, and decision-related outcomes. RESULTS: In the short term, the SDMI had no effect. In the long term, with respect to well-being, patients in the SDMI group had less intrusive thoughts (P =.05) and better general health (P =.01) and tended to be less depressed (P =.07). With respect to decision-related outcomes for the breasts, the SDMI group held stronger preferences (P =.02) and agreed more strongly to having weighed the pros and cons (P =.01). No effect was found on treatment choice. In the long term, interaction effects between the SDMI and cancer history were found. The SDMI showed an overall beneficial effect for unaffected women, whereas affected women tended to experience detrimental effects. CONCLUSION: We conclude that the SDMI improved decision making in unaffected BRCA1/2 mutation carriers. Supporting decision making in a systematic way using trade-offs is beneficial for these women.

Acute Q fever infection in Thuringia, Germany, after burial of roe deer fawn cadavers (Capreolus capreolus): a case report.

We report on a case of a 48-year-old man who presented with acute Q fever infection after burying two fawn cadavers (Capreolus capreolus). Recent outbreaks of Q fever in Europe have been traced back to intensive goat breeding units, sheep flocks in the proximity of highly populated urban areas or to farmed deer. To our knowledge, this is the first case report describing Q fever infection in a human linked to roe deer as a source of infection.

Acampomelic campomelic syndrome.

Campomelic syndrome (or campomelic dysostosis, CD; MIM *114290) is an autosomal dominant skeletal malformation syndrome characterized by shortness and bowing of long bones, especially of the lower limbs. Additional radiological and clinical findings are 11 pairs of ribs and a bell-shaped thorax, hypoplastic scapulae, narrow iliac wings, non-mineralized thoracic pedicles, clubbed feet, Robin sequence, typical facial anomalies and tracheomalacia. The disorder is frequently lethal due to respiratory distress. Sex reversal occurs in most patients with an XY karyotype. CD is caused by heterozygous mutations in the SOX9 gene, an SRY-related gene at 17q24.3-q25.1 with pleiotropic effects on the skeletal and genital systems. In addition, cases with chromosomal rearrangements involving 17q have been described that are most likely caused by disturbing one or more cis-regulatory elements from an extended control region. Campomelia (bowed limbs) is seen in most but not all patients, defining a so-called acampomelic campomelic dysostosis (ACD). Half of the CD cases with 17q rearrangements have no or mild campomelia. Furthermore, campomelia is absent or only mildly present in a small subgroup of cases with a normal karyotype. We present a chromosomally normal boy with ACD and his clinical follow-up up to the age of 2 years, in whom a heterozygous SOX9 missense mutation (H165Y) was identified. A SOX9 missense mutation was published in two other patients with ACD. Although up to now a general genotype-phenotype correlation could not be established for CD, a correlation emerges for the ACD variant that needs further confirmation.

Sibs with Axenfeld-Rieger anomaly, hydrocephalus, and leptomeningeal calcifications: a new autosomal recessive syndrome?

The Axenfeld-Rieger anomaly is a defect of the anterior chamber of the eye affecting the angle structures. If accompanied by hypodontia, midface hypoplasia, and umbilical anomalies, the designation "Rieger syndrome" is appropriate. Both conditions are autosomal dominant traits. The Axenfeld-Rieger anomaly is also known to occur in a variety of other syndromes. We report on two sisters, born to consanguineous parents, who presented with Axenfeld-Rieger anomaly, hydrocephalus, leptomeningeal calcifications, and mild mental retardation. Their height was on and just below the 3rd centile, respectively. One of them suffered from epilepsy and the other from sensorineural hearing loss. Two of their brothers died at young ages of hydrocephalus and possibly had intracranial calcifications as well. The differential diagnosis is discussed. Of the known syndromes associated with Axenfeld-Rieger anomaly, none could be convincingly applied to the propositae. Possibly, they represent a previously unreported autosomal recessive syndrome.

Duplication of chromosome region 8p23.1-->p23.3: a benign variant?

Chromosome analysis was performed in a 34-year-old man who was phenotypically normal except for oligoasthenozoospermia. In this patient, analysis of GTG-banded chromosomes showed in one chromosome 8 additional chromosomal material of unknown origin. To characterize the aberrant chromosome more precisely, a paint specific for chromosome region 8pter-->8p23.1 was generated by microdissection and degenerated oligonucleotide primed-polymerase chain reaction (DOP-PCR) and used as fluorescence in situ hybridization (FISH) paint. After reverse painting, hybridization signals were only found on the short arm of the two chromosomes 8, with an enlarged signal on the derivative chromosome 8. The duplication was characterized further with band-specific FISH probes. We concluded that (part of) chromosome region 8p23.1-->p23.3 was duplicated. Chromosome analysis of the parents showed that the dup(8) was of maternal origin and that the fertile brother of the index patient also was a carrier of the chromosome aberration. There was no history of miscarriages. We suggest that duplication of region 8p23.1-->p23.3 can be regarded as euchromatic variant or duplication with no phenotypic effect.

Familial dup(8)(p12p21.1): mild phenotypic effect and review of partial 8p duplications.

We describe a family with direct transmission of a duplication of 8p12-->8p21.1. The phenotype of affected relatives included mild mental retardation but no minor anomalies. The duplication was identified by means of GTG-banding and fluorescence in situ hybridization with a probe specific for 8p12 generated by microdissection and degenerate oligonucleotide primed-polymerase chain reaction. Assay of glutathione reductase, which has been localised to 8p21.1, was significantly increased when compared with controls with normal chromosomal constitution. To the best of our knowledge, a proximal direct duplication of 8p restricted to subbands p12-->p21.1 has not been reported so far. The reported aberration is compared with other partial duplications of 8p, in particular to inversion duplications 8p and to small direct distal duplications involving 8p23.1. Am. J. Med. Genet. 94:306-310, 2000.

Epidermolysis bullosa simplex with mottled pigmentation: clinical aspects and confirmation of the P24L mutation in the KRT5 gene in further patients.

Epidermolysis bullosa simplex with mottled pigmentation (EBS-MP) is a rare dermatologic disorder of autosomal dominant inheritance with intraepidermal blistering after minor trauma, reticular hyperpigmentation unrelated to the blistering, nail dystrophy, and mild palmoplantar keratosis. Keratin 5 and keratin 14 are known to be essential for the basal keratinocyte cytoskeleton and are defective in several forms of epidermolysis bullosa simplex. Recently, a 71C-->T transition in the keratin 5 gene (KRT5) causing a P24L substitution was identified in some patients with EBS-MP. We present a family with three affected members and a sporadic patient with EBS-MP. They exemplify clinically mild expression with intrafamilial variability and the possibility of improvement with time. In all of them, mutation analysis of the KRT5 gene showed the P24L mutation. So far, other mutations in the same or in other genes have not been reported in patients with EBS-MP.