Multiple malformations in a male and maternal osteopathia strata with cranial sclerosis (OSCS)

Osteopathia striata with cranial sclerosis (OSCS), conductive hearing impairment and a characteristic facial appearance is the clinical manifestation in carrier women of an X-linked disease. We report on a family with typical OSCS in the mother, a maternal aunt and the grandmother, and multiple severe malformations in the son. He was affected by cranial sclerosis with frontal bossing, conductive hearing impairment, cleft palate, thoracic dysplasia, mesenterium commune with non-rotation of the gut, anal atresia, bilateral cutaneous syndactyly of 3rd and 4th fingers, duplication of the distal phalanx of 2nd and 3rd fingers on the right, bilateral fibular aplasia with clubfeet, developmental retardation, epileptic seizures, hypothyroidism, and hypertrophic pyloric stenosis. The X-inactivation pattern in peripheral leucocytes of one informative carrier woman was random. Our case and several literature reports confirm that males which are hemizygous for the OSCS trait suffer from a dysmorphic syndrome with characteristic multiple malformations as a distinct entity. There is, at present, no reason to assume genetic heterogeneity with an autosomal dominant OSCS variant.

Osteopathia striata with cranial sclerosis: literature reappraisal argues for X-linked inheritance

Osteopathia striata with cranial sclerosis (OS-CS) is characterized by linear striations of tubular bones and fan-shaped configurations of the ilia. Although referred in literature as an autosomal dominant disorder the clinical pattern of partial involvement as well as the reported family observations plead for X-linked inheritance with mild striated bone affections in carrier women and severe syndromic morbidity and high mortality in the males. Sporadic affected males are probably somatic mosaics. There is no proven father-son transmission. Symptomatic osteopathia striata (OS) is characteristic in X-linked focal dermal hypoplasia Goltz-Gorlin.

Tuberous sclerosis type 1: three novel mutations detected in exon 15 by a combination of HDA and TGGE

Tuberous sclerosis (TSC) is an autosomal dominant disorder which is genetically heterogeneous with two genes, TSC1 and TSC2. TSC1 consists of 23 exons with exon 15 being the largest one comprising 559 bp. Representing 16% of the coding region exon 15 harbors 37% of the already identified point mutations in TSC1. Mutation screening of large DNA fragments as TSC1 exon 15 by SSCP has been a problem because of the low sensitivity of this method without subdivision. Therefore, we simultaneously performed heteroduplex analysis (HDA) and temperature gradient gel electrophoresis (TGGE) which are both more suitable for evaluation of fragments of this size. DNA samples of 159 patients with the clinical diagnosis of TSC were screened and a total of seven different mutations in nine unrelated cases were identified, including the three novel mutations 1754delT, 1836delT and R500Q. Comparing the two methods applied, HDA showed a higher sensitivity in detecting frameshift mutations, while TGGE seemed to be more sensitive for the detection of base exchanges. We conclude that the combination of these two methods is appropriate to reach a high degree of sensitivity for the detection of all types of small mutations in large DNA fragments.

International recommendations and guidelines for the safe use of diagnostic ultrasound in medicine

Modern sophisticated ultrasonographic equipment is capable of delivering substantial levels of acoustic energy into the body when used at maximum outputs. The risk of producing bioeffects has been studied by international expert groups during symposia supported by the World Federation for Ultrasound in Medicine and Biology (WFUMB). These have resulted in the publication of internationally accepted conclusions and recommendations. National ultrasound safety committees have published guidelines as well. These recommendations and safety guidelines offer valuable information to help users apply diagnostic ultrasound in a safe and effective manner. Acoustic output from ultrasound medical devices is directly regulated only in the USA and this is done by the Food and Drug Administration (FDA). However, there is also a modern trend towards self-regulation which has implications for the worldwide use of diagnostic ultrasound. It has resulted in a move away from the relatively simple scheme of FDA-enforced, application-specific limits on acoustic output to a scheme whereby risk of adverse effects of ultrasound exposure is assessed from information provided by the equipment in the form of a real-time display of safety indices. Under this option, the FDA allows a relaxation of some intensity limits, specifically approving the use of medical ultrasound devices that can expose the fetus or embryo to nearly eight times the intensity that was previously allowed. The shift of responsibility for risk assessment from a regulatory authority to the user creates an urgent need for awareness of risk and the development of knowledgeable and responsible attitudes to safety issues. To encourage this approach, it is incumbent on authorities, ultrasound societies and expert groups to provide relevant information on biological effects that might result from ultrasonographic procedures. It is obvious from the continued stream of enquiries received by ultrasound societies that effective dissemination of such knowledge requires sustained strenuous effort on the part of ultrasound safety committees. There is a strong need for continuing education to ensure that appropriate risk/benefit assessments are made by users based on an appropriate knowledge of the probability of biological effects occurring with each type of ultrasound procedure. The primary purpose of this paper is to draw attention to current safety guidelines and show the similarities and areas of general agreement with those issued by the parent ultrasound organisation, the WFUMB. It is equally important to identify gaps in our knowledge, where applicable.

Mutation screening of the entire coding regions of the TSC1 and the TSC2 gene with the protein truncation test (PTT) identifies frequent splicing defects

Mutation analyses in tuberous sclerosis (TSC) have reported a wide variety of disease-causing aberrations in the two known predisposing genes, TSC1 and TSC2 on chromosomes 9q34 and 16p13, comprising mainly small mutations distributed over the entire genes. So far, all known TSC1 mutations as well as the majority of TSC2 mutations truncate the proteins hamartin and tuberin, respectively. We describe for the first time an RNA-based screening of the entire coding regions of both TSC genes for truncating mutations applying the protein truncation test (PTT). Simultaneous investigation of both TSC genes in a group of 48 unassigned TSC patients, which were previously tested to exclude large intragenic TSC2 rearrangements, revealed aberrant migrating polypeptides resulting from truncating mutations in nine TSC1 cases and in 16 TSC2 cases while three TSC2 cases showed enlarged proteins. TSC1 mutations include two nonsense mutations, four insertions, and three splice mutations. Nineteen mutations identified in TSC2 were composed of four different nonsense mutations in five patients, one deletion, one insertion, and seven different splicing aberrations due to at least eight different mutations found in 12 patients. Additional predicted truncating mutations according to PTT without possible identification of the causative alteration allowed assignment to TSC1 in one and TSC2 in seven cases. Twelve patients without abnormalities in the PTT are assumed to harbor missense mutations, probably in TSC2. The high proportion of TSC2 splicing aberrations strengthens the importance of intronic disease-causing mutations and the application of RNA-based screening methods to confirm their consequences.

Extracutaneous analogies of Blaschko lines

In females, early random X-chromosome inactivation in the late blastocyst and subsequent embryonic development cause a random distribution of cells with an active paternal or maternal X-chromosome. Carriers of X-linked disorders are mostly healthy but, when thoroughly examined, may display a characteristic pattern of partial involvement, which for the skin, is known to follow the lines of Blaschko. Comparable patterns of involvement have been seen in various other organs. The evaluation of carriers who are heterozygous for X-linked disorders, therefore, is an efficient method for the study of functional genetic mosaicism in humans. The same patterns can also be seen in case of early embryonic somatic mutations.

[Lung hemorrhage caused by diagnostic ultrasound. Review of the literature]

In animals pulsed diagnostic ultrasound is capable of causing subpleural capillary lung bleeding if the pressure amplitude is above 1 MPa. Precondition is pulmonary ventilation; fetal organs are, therefore, not at risk. Capillary lung bleeding is a threshold effect depending on pressure amplitude and frequency. The degree of injury is apparently also influenced by the alveolar size. The same effect can be observed in the intestine at pressure amplitudes above 2 MPa. It is not known whether the effect is also caused by sonographic examination in humans. Should this be the case, the lesions would be of minor relevance and probably without any clinical symptoms. Nevertheless, during examination it would be advisable to restrict the ultrasound exposure of lung and intestine to the minimum necessary for reliable diagnosis.

The sensitivity of biological tissue to ultrasound

Mammalian tissues have differing sensitivities to damage by physical agents such as ultrasound. This article evaluates the scientific data in terms of known physical mechanisms of interaction and the impact on pre- and postnatal tissues. Actively dividing cells of the embryonic and fetal central nervous system are most readily disturbed. As a diagnostic ultrasound beam envelopes a small volume of tissue, it is possible that the effects of mild disturbance may not be detected unless major neural pathways are involved. There is evidence that ultrasound can be detected by the central nervous system; however, this does not necessarily imply that the bioeffect is hazardous to the fetus. Biologically significant temperature increases can occur at or near to bone in the fetus from the second trimester, if the beam is held stationary for more than 30 s in some pulsed Doppler applications. In this way, sensory organs that are encased in bone may be susceptible to heating by conduction. Reports in animals and humans of retarded growth and development following frequent exposures to diagnostic ultrasound, in the absence of significant heating, are difficult to explain from the current knowledge of ultrasound mechanisms. There is no evidence of cavitation effects occurring in the soft tissues of the fetus when exposed to diagnostic ultrasound; however, the possibility exists that such effects may be enhanced by the introduction of echo-contrast agents.

Mosaicism for the Charcot-Marie-Tooth disease type 1A duplication suggests somatic reversion

A female patient with clinical signs and symptoms of a demyelinating neuropathy was shown to have a duplication of the 1.5-Mb region on chromosome 17p11.2, typical of the great majority of cases of Charcot-Marie-Tooth disease type 1A (CMT1A). However, analysis of DNA extracted from peripheral blood revealed a 2:2.4 instead of the usual 2:3 ratio between the 7.8- and 6.0-kb EcoRI fragments in the proximal and distal repetitive extragenic palindromic (REP) elements of CMT1A. Detection of a 3.2-kb EcoRI/SacI kb junction fragment with probe pLR7.8 confirmed the CMT1A duplication. The dosage of this junction fragment, compared with a 2.8-kb EcoRI/SacI fragment of the proximal REP elements of CMT1A, was 2:0.58 instead of the expected 2:1 dosage for heterozygous CMT1A duplications. We hypothesized that the lower dosages of these restriction fragments specific for the CMT1A duplication were due to mosaicism; this was confirmed by fluorescence in situ hybridization analysis with the D17S122-specific probe pVAW409R1. In peripheral blood lymphocytes the percentage of interphase nuclei with a duplication in 17p11.2 was 49%. In interphase nuclei extracted from buccal mucosa, hair-root cells or paraffin-embedded nervous tissue the duplication was detectable in 51%, 66% and 74%, respectively. This is the first report of mosaicism in a patient with a CMT1A duplication identified by three different and independent techniques.

Specific acromesomelia with facial and renal anomalies: a new syndrome

A facio-renal-acromesomelic syndrome is reported in a 15-year-old boy with normal intelligence. The main dysmorphic features are a large head and congenital ptosis with telecanthus. There is unilateral ureteral stenosis with hydronephrosis. Bone abnormalities consist of ulnar dysplasia and tibial hypoplasia, multiple synostoses of carpal and tarsal bones, proximal synostoses of metatarsals, and of brachydactyly. A similar case has not been published.

Chromosomal mosaicism in two patients with epidermal verrucous nevus. Demonstration of chromosomal breakpoint

Linear epidermal nevi are hamartomas that originate in embryonic ectoderm. For epidermal nevi associated with involvement of other systems, such as the skeleton or central nervous system, the term epidermal nevus syndrome has been introduced. Chromosomal aberrations have been suggested but not proven as an underlying cause. We performed cytogenetic studies of skin cells from two unrelated men who had a verruciform epidermal nevus. Variegated translocation mosaicism with an identical breakpoint localized at the long arm of chromosome 1 was present in both patients. Normal skin and blood lymphocytes showed normal karyotypes.

Hydantoin syndrome with holoprosencephaly: a possible rare teratogenic effect

We report on a newborn girl with lobar holoprosencephaly and clinical signs of hydantoin syndrome. During pregnancy the mother was treated with diphenylhydantoin and primidon for psychomotor and petit mal seizures. The possible relationship between hydantoin syndrome, holoprosencephaly, and maternal intake of anticonvulsants during pregnancy is discussed.

A microdeletion of less than 250 kb, including the proximal part of the FMR-I gene and the fragile-X site, in a male with the clinical phenotype of fragile-X syndrome

A gene designated "FMR-1" has been isolated at the fragile-X locus. One exon of this gene is carried on a 5.1-kb EcoRI fragment that exhibits length variation in fragile-X patients because of amplification of or insertion into a CGG-repeat sequence. This repeat probably represents the fragile site. The EcoRI fragment also includes an HTF island that is hypermethylated in fragile-X patients showing absence of FMR-1 mRNA. In this paper, we present further evidence that the FMR-1 gene is involved in the clinical manifestation of the fragile-X syndrome and also in the expression of the cellular phenotype. A deletion including the HTF island and exons of the FMR-1 gene was detected in a fragile X-negative mentally retarded male who presented the clinical phenotype of the fragile-X syndrome. The deletion involves less than 250 kb of genomic DNA, including DXS548 and at least five exons of the FMR-1 gene. These data support the hypothesis that loss of function of the FMR-1 gene leads to the clinical phenotype of the fragile-X syndrome. In the fragile-X syndrome, there are pathogenetic mechanisms other than amplification of the CGG repeat that do have the same phenotypic consequences.

A study of ten small supernumerary (marker) chromosomes identified by fluorescence in situ hybridization (FISH)

In seven cases additional minute chromosomes studied by FISH were identified as no. 3, 11, 15, 18, 21 and X. Findings were unexpected except for partial trisomy 21 in an adolescent with minor features of Down's syndrome. Moreover, an i(18p) in a mentally retarded dysmorphic child and an idic(15) in a child with Fallot tetralogy was confirmed. In a child with r(21), a supernumerary marker was shown to be derived from no. 21, while in the mother an additional marker idic(22) was noted.

A third gene locus for tuberous sclerosis is closely linked to the phenylalanine hydroxylase gene locus

Following the observation of a patient suffering from tuberous sclerosis (TSC) with a de novo reciprocal translocation t(3;12) (p26.3;q23.3), we have undertaken a linkage study in 15 TSC families using polymorphic DNA markers neighbouring the chromosome breakpoints. Significant lod scores have been obtained for markers D12S7 (Zmax = 2.34, theta = 0.14) and PAH (phenylalanine hydroxylase (Zmax = 4.34, theta = 0.0). In multipoint linkage analysis, the peak lod score was 4.56 at the PAH gene locus. These data suggest the existence of a third gene locus for TSC (TSC3) on chromosome 12q22-24.1. The regions that have been found to be linked to TSC in different families map to the positions of three enzymes, phenylalanine hydroxylase (12q22-24), tyrosinase (11q14-22), and dopamine-beta-hydroxylase (9q34), all of which are involved in the conversion of phenylalanine to catecholamine neurotransmitters or melanin. Disorders of these biochemical pathways might be involved in the pathogenesis of TSC.

Tuberous sclerosis in a child with de novo translocation t(3;12) (p26.3;q23.3)

We report on an 8-year-old boy with severe mental retardation, epileptic seizures, autistic behaviour, and X-ray CT findings of the skull characteristics for tuberous sclerosis. At the age of 9 years, first signs of adenoma sebaceum developed. Chromosomal analysis revealed a translocation t(3;12)(p26.3;q23.3). The parents were both healthy and had normal karyotypes. As non-random association of a chromosomal abnormality and tuberous sclerosis is hypothesized, a third locus for this disorder on 3p26 or 12q23 has to be taken in account.

Keratotorus in Norrie disease

We report on a 46-year old white male with Norrie disease. In the right eye he had a keratotorus with non vascularized corneal scars and mature cataract. After penetrating keratoplasty a pseudoglioma with irreversible total retinal detachment was found. The left eye had phthisis bulbi with corneal pannus and band keratopathy, shallow anterior chamber, posterior synechia and mature cataract.

Tuberous sclerosis in two sibs of normal parents

We report on a family with two sibs suffering from tuberous sclerosis. The parents were normal in all clinical tests including Wood's light examination of the skin, ophthalmoscopy, X-ray computerized tomography of brain, liver, and kidneys, cardiac echography and MR imaging of the brain. The most likely explanation is a germinal cell mosaic in one of the parents. A recurrence risk of 20 to 37% seems appropriate. The implications for risk assessment of sporadic cases are emphasized.

X-linked ocular albinism. Characteristic pattern of affection in female carriers

The authors report on a family with X-linked ocular albinism. Examined were one of three affected males and eight females. Six women were carriers and showed iris retroillumination and typical abnormalities of the fundus. The patchy or striated hypopigmentation of the retinal pigment epithelium is thought to be due to random inactivation of the paternal or maternal X-chromosome respectively. The pattern of affection however represents a nonrandom embryological developmental pattern of the retinal pigment epithelium.

Hypomelanosis of Ito (incontinentia pigmenti achromians). Ophthalmological evidence for somatic mosaicism

The authors report on a ten-year-old boy with hypomelanosis of Ito. He suffered from epileptic seizures and exhibited typical generalized partial skin hypomelanosis in whorl-like and striated pattern following Blaschko's lines. The fundi showed patchy, mottled hypopigmentations becoming increasingly striated in the periphery with a general orientation to the optic nerve head. This pattern of affection reminds of the retinal findings in carrier women for X-linked ocular albinism. Magnetic resonance imaging revealed multiple small areas of increased relaxation time scattered in the white matter of the brain, which are interpreted as porencephalic cysts. These clinical findings suggest somatic cell mosaicism even though the cytogenetic study was not conclusive.

Ocular hypotelorism, submucosal cleft palate, and hypospadias: a new autosomal dominant syndrome

A syndrome characterized by ocular hypotelorism, submucosal cleft palate, and hypospadias in males was found in ten relatives over five generations of a family. Other anomalies are blepharophimosis, upslant of palpebral fissures, and a tendency to cutaneous syndactyly of 3rd and 4th fingers as well as 2nd and 3rd toes. Autosomal dominant inheritance is likely.

[Analogy of Blaschko lines in the eye]

In females random X-inactivation and subsequent embryonic development cause a specific distribution of cell clones. This aspect can be seen in carrier women for different X-linked diseases. In such dermopathies the carrier women show striated skin affections following a system of lines, which has been described by A. Blaschko in 1901. An analogous pattern can be seen in the retina of carrier women for the X-linked ocular albinism. The fundus shows a partial involvement with a striated pattern diverging from the papilla. In X-linked cataracts carrier women have lens opacities with an irregularly radiated pattern as well as segmental cataracts. This finding is demonstrated in the isolated X-linked cataract, the X-linked chondrodysplasia punctata, and in Lowe's syndrome.

Imaging technics in muscular dystrophies

Modern medical imaging technics as ultrasound and computerized tomographies with X-rays, nuclear magnetic resonance or ultrasound permit the representation of soft tissues including muscles. For muscular dystrophies, these diagnostic methods may allow a more detailed staging and evaluation of single muscle groups. The value for Duchenne carrier detection has meanwhile been proven.

[The Lyon effect of the lens: findings in the carriers of X chromosome-linked cataract and in Lowe syndrome]

In carrier women for X-linked diseases the random X-inactivation and the subsequent embryonic process of development and differentiation induce characteristic patterns of tissue mosaicism. In the lens, the random mosaic pattern of equatorial epithelial cells and their proliferation oriented toward the posterior pole induce a radial or segmental distribution pattern of clonal cell populations. This can be shown in carrier women for X-linked cataracts. Findings in a carrier woman for X-linked cataract and for Lowe's syndrome respectively are reported.

Observation concerning the age of onset and the nature of optic atrophy in Wolfram's syndrome (DIDMOADS)

A 31/2-year-old boy, who was diagnosed to have diabetes 6 months earlier, was referred for routine fundus check-up. No family history of diabetes was known. Ophthalmologic findings were: slight hyperopic astigmatism, visual acuity right = left = 1/5, examination of the visual field not yet possible, optic atrophy, no diabetic retinopathy, very narrow vessels. ERG: distinctly reduced potentials. Audiogram: loss of high tones in the inner ear. Pediatric examination ruled out other endocrine disorders, no symptoms of diabetes insipidus were found. These results perhaps reveal the nature of the optic atrophy: a retinal one. The authors found no other ERGs in the literature at such an early stage.

Duchenne's muscular dystrophy: carrier detection by imaging technics

The partial muscular dystrophic process in carrier women for X-linked muscular dystrophy, which results in an increased fatty and connective tissue infiltration of thigh and calf muscles, can be shown by ultrasound and X-ray CT. These technics are of special value in older women, where CK levels have normalized. Age dependencies and the consequences for genetic counseling will be discussed.

Partial sweat gland aplasia in incontinentia pigmenti Bloch-Sulzberger. Implications for nosologic classification

Dermatoglyphic investigation of palm prints in patients with Incontinentia pigmenti revealed in five of eight cases a partial ridge dissociation with lack of sweat gland pores. This disease can, therefore, be accepted as a second X-linked anhidrotic ectodermal dysplasia, which, however, is only segregated in the female.

[Carrier state in X-linked ocular albinism: a proof of the validity of Lyon's hypothesis in man]

The finding of an irregular patchy fundus pigmentation in the mother of a boy with ocular albinism was interpreted as Lyon's effect on the fundus, i.e., the mosaic-like effect caused by a pathologic X-chromosome in the female carrier. It was thus possible to diagnose the more frequent X-linked form in this family.