Hypomelanosis of Ito: no entity, but a cutaneous sign of mosaicism

Elastic Gallium Phosphide Nanowire Optical Waveguides-Versatile Subwavelength Platform for Integrated Photonics

Emerging technologies for integrated optical circuits demand novel approaches and materials. This includes a search for nanoscale waveguides that should satisfy criteria of high optical density, small cross-section, technological feasibility and structural perfection. All these criteria are met with self-assembled gallium phosphide (GaP) epitaxial nanowires. In this work, the effects of the nanowire geometry on their waveguiding properties are studied both experimentally and numerically. Cut-off wavelength dependence on the nanowire diameter is analyzed to demonstrate the pathways for fabrication of low-loss and subwavelength cross-section waveguides for visible and near-infrared (IR) ranges. Probing the waveguides with a supercontinuum laser unveils the filtering properties of the nanowires due to their resonant action. The nanowires exhibit perfect elasticity allowing fabrication of curved waveguides. It is demonstrated that for the nanowire diameters exceeding the cut-off value, the bending does not sufficiently reduce the field confinement promoting applicability of the approach for the development of nanoscale waveguides with a preassigned geometry. Optical X-coupler made of two GaP nanowires allowing for spectral separation of the signal is fabricated. The results of this work open new ways for the utilization of GaP nanowires as elements of advanced photonic logic circuits and nanoscale interferometers.

Monogenic causes of pigmentary mosaicism

Pigmentary mosaicism of the Ito type, also known as hypomelanosis of Ito, is a neurocutaneous syndrome considered to be predominantly caused by somatic chromosomal mosaicism. However, a few monogenic causes of pigmentary mosaicism have been recently reported. Eleven unrelated individuals with pigmentary mosaicism (mostly hypopigmented skin) were recruited for this study. Skin punch biopsies of the probands and trio-based blood samples (from probands and both biological parents) were collected, and genomic DNA was extracted and analyzed by exome sequencing. In all patients, plausible monogenic causes were detected with somatic and germline variants identified in five and six patients, respectively. Among the somatic variants, four patients had MTOR variant (36%) and another had an RHOA variant. De novo germline variants in USP9X, TFE3, and KCNQ5 were detected in two, one, and one patients, respectively. A maternally inherited PHF6 variant was detected in one patient with hyperpigmented skin. Compound heterozygous GTF3C5 variants were highlighted as strong candidates in the remaining patient. Exome sequencing, using patients' blood and skin samples is highly recommended as the first choice for detecting causative genetic variants of pigmentary mosaicism.

A novel pathogenic RHOA variant in a patient with patterned cutaneous hypopigmentation associated with extracutaneous findings

RHOA-related neuroectodermal syndrome is characterised by linear skin hypopigmentation along Blaschko's lines associated with alopecia, leukoencephalopathy, facial and limb hypoplasia, and ocular, dental, and acral anomalies. Herein, we report a patient with patterned cutaneous hypopigmentation with a similar phenotype due to a novel postzygotic RHOA variant (c.210G>T; p.Arg70Ser). This illustrates that the complexity of the orchestration of morphogenesis and organogenesis can be affected by different variants in the same gene.

Genetic and clinical characterization of 73 Pigmentary Mosaicism patients: revealing the genetic basis of clinical manifestations

BACKGROUND

Pigmentary mosaicism constitutes a heterogeneous group of skin pigmentation alterations associated with multisystem involvement. The aim of this study was to establish a complete cytogenetic and molecular characterization of PM patients, emphasizing on searching for possible low chromosomal mosaicism and on establishing an accurate genotype-phenotype correlation.

RESULTS

A total of 73 patients were included (3 months to 18 years of age), 52% male and 48% female. Observed in 69 (95%) patients, the most frequent pattern of pigmentation was fine and whorled BL, which was associated with disseminated skin extent in 41 (59%) patients. Central nervous system (84%) alterations were the most frequent observed in the group of patients, followed by the musculoskeletal (53%) and ophthalmologic (27%) alterations. Considering the pattern of pigmentation, no significant differences in association with skin extent or extracutaneous manifestations were detected. Following a strict cytogenetic analysis strategy, screening metaphases from three different tissues (peripheral blood, hyperpigmented and hypopigmented skin) we found that 23/73 patients had chromosomal abnormalities classified as follows: 1) Mosaic with 2 or more different cell lines with structural alterations n = 19; 2) Polyploidy (mosaic) n = 1 and 3) Alterations in all cells in three different tissues n = 3. SNP array, array CGH and FISH were useful for the complete characterization of the chromosomal aberrations, for the detection of microdeletions in patients with normal karyotype but with strong clinical suspicious of chromosomal alteration, and for a better establishment of genotype-phenotype correlation. In 2 patients we found genes associated with some of the extracutaneous manifestations (SHH, MNX1, PPP2R2C).

CONCLUSIONS

This group of 73 patients finely described is the largest series of patients with pigmentary mosaicism reported worldwide. As we showed in this study, the followed analysis strategy allowed the detection of cytogenetic and molecular abnormalities, and made possible the establishment of genotype-phenotype associations in some patients. An important limitation of our study was the analysis of fibroblasts cultures instead of melanocytes and keratinocytes. In some cases the direct molecular DNA analysis of skin biopsy could be another choice.

Palmoplantar depigmentation in Macaca fascicularis following Blaschko linear pattern

Hypomelanosis of Ito is a rare neurocutaneous syndrome, characterized by streaks and swirls of hypopigmentation arranged in a Blaschkoid pattern. Other associated anomalies are observed. We report a case of a male cynomolgus monkey (Macaca fascicularis) who presented the characteristic of hypomelanosis of Ito with palmoplantar involvement and polythelia.

Hypomelanosis of Ito with Multiple Congenital Anomalies

Hypomelanosis of Ito (HI) is a neurocutaneous disorder, also known as incontinentia pigmenti achromians. HI has been associated with chromosomal abnormalities, especially mosaicism. Herein, we report a case of HI with multiple congenital anomalies. A 2-month-old girl presented with multiple linear and whorling hypopigmentation on the face, trunk, and both extremities and patch alopecia on the scalp. Moreover, she had conical teeth, aniridia of the both eyes, and multiple musculoskeletal problems, including syndactyly and coccyx deviation. Cytogenetic analysis on peripheral blood was normal 46, XX, and no mutation was found in IKBKG gene test.

A case of hypomelanosis of Ito accompanied by unilateral abnormal limb overgrowth and delayed speech

Hypomelanosis of Ito (HI) is characterized by unilateral or bilateral hypopigmented skin lesions and usually presents as a multisystemic disorder. Skin lesions may develop in different textures, such as linear, whorled, or patchy, and are often accompanied by abnormalities of the central nervous system, skeletal system, eyes, and teeth. HI is associated with sporadic gene mutations but not gender. Presentation of the current case may be of use in reminding practitioners of the common extracutaneous findings of HI, along with some rare manifestations, such as delayed speech and asymmetric limb growth.

Total Hemi-overgrowth in Pigmentary Mosaicism of the (Hypomelanosis of) Ito Type: Eight Case Reports

Pigmentary mosaicism of the (hypomelanosis of) Ito type is an umbrella term, which includes phenotypes characterized by mosaic hypopigmentation in the form of streaks, whorls, patchy, or more bizarre skin configurations (running along the lines of Blaschko): these cutaneous patterns can manifest as an isolated skin disorder (pigmentary mosaicism of the Ito type) or as a complex malformation syndrome in association with extracutaneous anomalies (most often of the musculoskeletal and/or nervous systems) (hypomelanosis of Ito). Affected individuals are anecdotally reported to have also partial or total body hemi-overgrowth (HOG), which often causes moderate to severe complications.We studied the occurrence and features of HOG in the 114 children and adults with mosaic pigmentary disorders of the Ito type diagnosed and followed up (from 2 to 22 years; average follow-up 16 years) at our Institutions.Eight patients (5 M, 3 F; aged 4 to 25 years; median age 16 years) out of the 114 analyzed (7%) fulfilled the criteria for unilateral HOG, with differences in diameter ranging from 0.4 to 4.0 cm (upper limbs) and 1.0 to 9.0 cm (lower limbs). Moreover, among these 8 patients, 5/8 filled in the 75th to 90th percentile for height; 6/8 had associated kyphoscoliosis; and 5/8 showed cognitive delays. No tumour complications were recorded. Overall, 6/8 HOG patients presented with additional (extracutaneous) syndromic manifestations, apart from the HOG (ie, with a clinical phenotype of hypomelanosis of Ito).The present study, which includes children and adults with the longest follow-up so far recorded, confirms the association between pigmentary mosaicism of the Ito type and HOG lowering previous estimates (7% vs 16%) for HOG in the context of mosaic hypopigmentation. A careful examination, looking at subtle to moderate asymmetries and associated complications within the spectrum of these mosaic pigmentary disorders, is recommended.

Hypomelanosis of Ito: a round on the frequency and type of epileptic complications

There is an ample evidence that hypopigmentation of the skin along the Blaschko's lines is frequently associated with neurological disorders. Nowadays, the term "Hypomelanosis of Ito" (HI) is applied when, together with the cutaneous lesions, various and multisystem organs are involved. Among these, the most frequent are cerebral manifestations, such as cognitive delay and epileptic seizures. For this reason, hypomelanosis of Ito has been included in the group of neurocutaneous syndromes, neurologic manifestations being one of the most frequent. Epileptic seizures have been reported in patients with this disorder, but in a very few particular attention has been focused on the type and frequency of epilepsy and on the response to the treatment. Herein, we report on five patients with HI who showed episodes of epileptic seizures with onset in childhood, in absence of malformative anomalies except for the skin lesions. A survey on the frequency and types of epileptic seizures in HI children and in the literature is reported.

Choroid plexus papilloma in a girl with hypomelanosis of Ito

The authors report a case of choroid plexus papilloma in a girl with hypomelanosis of Ito, and they review the literature in brief. Hypomelanosis of Ito is a rare neurocutaneous syndrome characterized by cutaneous hypopigmented whorls, streaks, and patches along lines of Blaschko. Most patients exhibit CNS manifestations, including psychomotor retardation, seizures, hypotonia, and ataxia. A 6-year-old girl with hypomelanosis of Ito was referred to the authors' hospital with bilateral tumors in the lateral ventricles. The right lateral ventricle tumor was surgically removed. Immunohistochemical investigations revealed the tumor to be a choroid plexus papilloma (WHO Grade I). A chromosomal investigation revealed that the tumor tissue demonstrated a large loss of heterozygosity at chromosome 10. The case reported here serves as a reminder that de novo brain tumors may arise in patients with chromosomal mosaicism.

Congenital ocular anomaly in an infant with trisomy 14 mosaicism

Trisomy 14 mosaicism is a rare chromosomal abnormality with distinct and recognizable clinical features. We report a patient with presumed retinal dystrophy having diffuse retinal pigment epithelial abnormalities, which has not been previously reported in association with trisomy 14. This case expands the clinical spectrum of this rare entity.

Retinoblastoma presenting in a child with hypomelanosis of Ito

Purpose:

To describe a case of a child with a known history of pigmentary mosaicism suggestive of Hypomelanosis of Ito presenting with unilateral leukocoria, who was ultimately diagnosed with retinoblastoma.

Methods:

A report of a 16-month-old girl with pigmentary mosaicism and unilateral retinoblastoma.

Results:

A previously healthy 16-month-old girl with a diagnosis of a mosaic hypopigmentation at the age of 6 months based on a linear and whorled pattern of skin hypopigmentation along the lines of Blaschko, presented with unilateral strabismus, leukocoria, retinal detachment, and sub-retinal exudation. Hypomelanosis of Ito and other similar neurocutaneous syndromes are known to be associated with abnormal retinal pigmentation, vascular abnormalities, and retinal detachment. Examination included a fluorescein angiogram, ultrasonography, and an MRI of the brain and orbits that demonstrated features consistent with retinoblastoma.

Given these findings and a flat electroretinogram, the eye was enucleated with final pathologic confirmation of retinoblastoma.

Conclusions:

Previously unreported presentation of unilateral retinoblastoma in a child with pigmentary mosaicism.

New association between ring chromosome 20 syndrome and hypomelanosis of Ito

Hypomelanosis of Ito is an uncommon neuroectodermal disease associated with a wide range of cytogenetic abnormalities. Ring chromosome 20 is a rare chromosomal disorder characterized by severe, refractory epilepsy, cognitive delay, and unspecific dysmorphic traits. An association between the hypomelanosis of Ito and ring chromosome 20 syndrome was never reported peviously. We describe a young girl who has ring chromosome 20 and who also has clinical symptoms of hypomelanosis of Ito. After her diagnosis of epilepsy, she was submitted to neurologic and genetic testing, a skin biopsy, and repeated neuropsychologic examinations. Karyotyping revealed a 46 XX, r(20) with mosaicism in 34% of peripheral blood lymphocytes and 8% of skin fibroblasts. A severe, progressive cognitive deterioration was evident. The epilepsy was refractory to antiepileptic drugs, in apparent contrast with the evidence that both telomeric regions were preserved. The percentage of mosaicism seems unrelated to the severity of the clinical phenotype.

Importância da análise cromossômica dos fibroblastos em casos suspeitos de mosaicismo: experiência de um serviço de Genética Clínica

OBJETIVOS: Verificar características clínicas e achados citogenéticos de pacientes com suspeita de mosaicismo submetidos à avaliação cromossômica por meio do cariótipo por bandas GTG de linfócitos e fibroblastos. MÉTODOS: Realizou-se uma análise retrospectiva dos pacientes avaliados no Serviço de Genética Clínica do Complexo Hospitalar Santa Casa de Porto Alegre da Universidade Federal de Ciências da Saúde de Porto Alegre, entre 1975 e 2009, por meio da coleta de dados clínicos e resultados da avaliação citogenética. RESULTADOS: A amostra foi composta de 15 pacientes, seis (40%) do sexo masculino, e idades variando de dez dias a 14 anos. Na análise cromossômica do sangue, alterações foram observadas em quatro pacientes (26,7%), incluindo-se um caso de translocação balanceada [t(2;9)pat] e três de mosaicismo [um caso, respectivamente, de mos 45,X/46,X,+mar; mos 46,XY,r(12)/45,XY,-12/47,XY,r(12),+r(12) e mos 46,XY/47,XY,+9]. Com o objetivo de confirmar ou mesmo identificar um mosaicismo cromossômico, os pacientes foram submetidos posteriormente ao cariótipo de pele. Os principais motivos pelos quais os pacientes com cariótipo do sangue sem mosaicismo apresentaram tal suspeita foram a presença de hemi-hipertrofia (n=5) e de manchas hipocrômicas seguindo as linhas de Blaschko (n=4). Mosaicismo foi confirmado em dois casos e identificado em outros dois (dois casos de mos 46,XX/47,XX,+22). O mos 46,XY/47,XY,+9 não foi verificado no estudo dos fibroblastos. CONCLUSÕES: Os resultados ilustram a variabilidade tecidual característica dos casos de mosaicismo cromossômico, bem como confirmam a importância da avaliação de um segundo tecido para a determinação diagnóstica. Achados clínicos, como assimetria de membros e anomalias pigmentares seguindo as linhas de Blaschko, são fortemente indicativos da presença de mosaicismo.

Hypomelanosis of Ito and Sturge-Weber syndrome without facial nevus: an association or a new syndrome?

Sturge-Weber syndrome without facial nevus is rare. Twenty-four cases were previously reported. Although hypomelanosis of Ito is a relatively common disorder, there was only one previous case in association with Sturge-Weber syndrome. We describe an 11-year-old boy with Sturge-Weber syndrome without facial nevus, coexistent with hypomelanosis of Ito.

Hypomelanosis of ito-whorled hyperpigmentation combination: a mirror image presentation

We hereby report a 2-year-old boy who presented with a peculiar combination of hyperpigmented and hypopigmented skin lesions along the lines of Blaschko, sharply demarcated at the midline, both on the anterior and posterior trunk. Although combinations of hyperpigmented and hypopigmented skin lesions distributed along the lines of Blaschko have been described, the combination of skin lesion comprised hypomelanosis of Ito and whorled hypermelanosis distributed in the extremely unusual manner described in this patient has not been reported previously.

Childhood autism and associated comorbidities

Autism is a heterogeneous neurodevelopmental disorder with a variety of different etiologies, but with a heritability estimate of more than 90%. Although the strong correlation between autism and genetic factors has been long established, the exact genetic background of autism is still unclear. This review refers to all the genetic syndromes that have been described in children with pervasive developmental disorders (tuberous sclerosis, fragile X, Down, neurofibromatosis, Angelman, Prader-Willi, Gilles de la Tourette, Williams, etc.). Issues covered include prevalence and main characteristics of each syndrome, as well as the possible base of its association with autism in terms of contribution to the current knowledge on the etiology and genetic base of pervasive developmental disorders.

High resolution microarray CGH and MLPA analysis for improved genotype/phenotype evaluation of two childhood genetic disorder cases: ring chromosome 19 and partial duplication 2q

A detailed analysis of the constitutional chromosomal changes in two pediatric patients was performed using high resolution genetic analysis techniques, microarray comparative genomic hybridization (array CGH) and multiplex ligation-dependent probe amplification (MLPA) as well as FISH. The aim was to come to a more precise characterization of the genotype/phenotype relationship. Case 1 was a girl of 25 months, showing areas of hypopigmentation along the lines of Blaschko and no other developmental abnormality. She carried a ring chromosome 19 which we found not to have resulted in loss of subtelomeric sequences, ruling out the possibility that a small subtelomeric loss was causally related to this patient's phenotype. Case 2 was a 9-year-old girl with facial anomalies and mild growth and mental retardation carrying an unidentified addition on chromosome 2p. We found that the addition was duplicated 2q35-q37.3 and that the addition was not accompanied by loss of 2pter or any other chromosomal region. Together with literature data, we hypothesize that pediatric patients with 'pure' trisomy 2q including bands 2q35-q37.1 may have a moderate clinical phenotype as opposed to patients with duplications proximal to 2q33 or patients with duplications 2q3 with accompanying distal deletion. These two examples illustrate the additional value of new, high resolution genetic analysis techniques for a better characterization of the genotype/phenotype relationship in childhood chromosomal disorders.

Genetic disorders of pigmentation

More than 127 loci are actually known to affect pigmentation in mouse when they are mutated. From embryogenesis to transfer of melanin to the keratinocytes or melanocytes survival, any defect is able to alter the pigmentation process. Many gene mutations are now described, but the function of their product protein and their implication in melanogenesis are only partially understood. Each genetic pigmentation disorder brings new clues in the understanding of the pigmentation process. According to the main genodermatoses known to induce hypo- or hyperpigmentation, we emphasize in this review the last advances in the understanding of the physiopathology of these diseases and try to connect, when possible, the mutation to the clinical phenotype.

[The skin as an expression of neurological alterations in the neonate]

The skin is involved in many different genetic syndromes and diseases with multiple organ involvement. Neurodevelopmental disorders appear in many of these entities and knowledge of these cutaneous alterations may provide clues to their diagnosis. Recognizing these skin disorders in the newborn allows early identification of neonates with a biological risk of epilepsy and motor and/or cognitive disorders and enables them to be followed up. This helps to plan the management of these patients and, in many entities, to predict their natural history and provide genetic counseling to the family. This review examines the cutaneous signs that may provide important clues in the neonate that help to identify entities that carry a risk of neurodevelopmental disorders in the neonate.

Pigmentary mosaicism following the lines of Blaschko in a girl with a double aneuploidy mosaicism: (47,XX,+7/45,X)

We report on a 6-year-old girl with linear streaks of apparent hypopigmentation and hyperpigmentation following the Blaschko lines, growth retardation, bupthalmos of the left eye, and mild mental retardation. She had a 45,X karyotype in lymphocytes. In cultured fibroblasts a double aneuploidy mosaicism was detected, consisting of a cell line with trisomy for chromosome 7 and a cell line with monosomy for the X-chromosome and no cell line with a normal karyotype. Cutis tricolor or three levels of pigmentation in different skin areas suggested presence of a third, probably normal cell line. Double aneuploidy mosaicism of a cell line with monosomy X and a cell line with trisomy of an autosome is a rare finding. The combination of monosomy X with trisomy of chromosomes 8, 10, 13, 18, and 21 has been reported, but not the combination with trisomy 7. In the 45,X cell line, microsatellite analysis showed loss of the maternal X-chromosome, and presence of a maternal and paternal chromosome 7. The 47,XX,+7 cell line showed a paternal and a maternal X-chromosome, and a paternal and two identical maternal chromosomes 7. Mechanisms that might explain this double aneuploidy mosaicism are discussed.

Skin diseases described in Japan 2004. In Japan beschriebene Dermatosen 2004

During the last century of modern dermatology, more than 30 skin diseases have been described first by physicians from Japan. Many of those conditions were disorders of pigmentation and keratinization, which are quite common in Oriental patients. Since the late 1940s, a number of skin diseases first reported in Japan have gained attention internationally among them being Kimura disease, hypomelanosis of Ito, Kawasaki disease, adult T-cell leukemia/ lymphoma, eosinophilic pustular folliculitis, prurigo pigmentosa, and Ofuji's papuloerythroderma. In this article, we review skin diseases that were first established as distinct entities in Japan, in order to familiarize readers of the Western literature with these conditions.

Unilateral linear hyperpigmentation of the skin with ipsilateral sectorial hyperpigmentation of the retina

A 32-year-old Caucasian man had a mosaic hyperpigmentation on his left arm, arranged in a pattern following the lines of Blaschko. In addition, a mosaic hyperpigmentation was noted in his left eye, in the form of grouped congenital hypertrophy of the retinal pigment epithelium (CHRPE). Such "bear tracks" are segmentally oriented, well-demarcated, flat, hyperpigmented lesions originating with small dots at the optic disk and expanding towards the periphery. We hypothesize that these mosaic pigmentary lesions involving the skin and the eye on the same side of the body may have originated from an early postzygotic mutation and thus may be etiologically related.

Trisomy 14 mosaicism: a case report and review of the literature

Trisomy 14 mosaicism is a rare chromosomal abnormality with distinct and recognizable clinical features. We describe two previously unreported abnormalities in this condition and delineate physical and psychomotor features and concerns for medical management. Trisomy 14 mosaicism should be suspected in individuals who have the features described herein, thus prompting cytogenetic evaluation of blood, and possibly other tissues for diagnosis.

Growth hormone deficiency (GHD): A new association in Peters' plus syndrome (PPS)

We report a case of a girl with clinical features of Peters' Plus Syndrome (PPS) (association of anterior eye chamber defects; peculiar facies; cleft lip/palate; brachymelia; developmental delay; growth retardation) and documented growth hormone deficiency (height -3.5 SDS at chronological age 5 years 8 months; low growth factors; bone age delay; growth velocity 4.4 cm/year (<3rd centile); and peak growth hormone levels of 1.7 and 4.7 ng/ml by clonidine and insulin provocative testing, respectively). Treatment with recombinant human growth hormone (0.3 mg/kg/week) resulted in a dramatic increase in growth velocity, increasing the height from -3.5 to -1.5 SDS over 2.3 years of therapy, indicative of an excellent response. Growth retardation is a known association in PPS: a condition that includes other midline facial defects. This case supports a role for GHD in the pathogenesis of the short stature observed in these children; demonstrates the efficacy of GH treatment; and further reinforces the relationship of pituitary anomalies with common congenital defects.

Primer on medical genomics. Part VIII: Essentials of medical genetics for the practicing physician

After the mapping and sequencing of the human genome, medical professionals from essentially all specialties turned their attention to investigating the role genes play in health and disease. Until recently, medical genetics was considered a specialty of minor practical relevance. This view has changed with the development of new diagnostic and therapeutic possibilities. It is now realized that genetic disease represents an important part of medical practice. Achievements in cancer genetics, in the field of prenatal diagnostics (including carrier testing for common recessive disorders), and in newborn screening for treatable metabolic disorders reinforce the rapidly expanding role of genetics in medicine. Diagnosing a genetic disorder not only allows for disease-specific management options but also has implications for the affected individual's entire family. A working understanding of the underlying concepts of genetic disease with regard to chromosome, single gene, mitochondrial, and multifactorial disorders is necessary for today's practicing physician. Routine clinical practice in virtually all medical specialties will soon require integration of these fundamental concepts for use in accurate diagnosis and ensuring appropriate referrals for patients with genetic disease and their families.

Hypomelanosis of Ito with Sturge-Weber syndrome-like leptomeningeal angiomatosis

The term hypomelanosis of Ito (HI) is applied to individuals with skin hypopigmentation following the lines of Blaschko (type 1a of patterns indicative of somatic mosaicism as defined by Happle). Even though originally described as a purely cutaneous disease, subsequent reports of HI have included a 30-94% association with multiple extracutaneous manifestations. The frequency of extracutaneous associations has led many authors to consider HI to be neurocutaneous disorder. We report a male infant with cutaneous hypomelanosis along the lines of Blaschko distributed on the left half of the body who developed status epilepticus. Neuroimaging studies disclosed an angiomatous enlargement of the right choroid plexus and a gyral pattern of cortical and subcortical calcification in the right occipital region. Thus a diagnosis could be made of HI and associated Sturge-Weber syndrome-like leptomeningeal angiomatosis. This previously unreported association lends further support to the consideration of hypomelanosis of Ito as a marker of somatic mosaicism with frequently associated neurologic abnormalities. A relationship between HI and Sturge-Weber syndrome, two neuroectodermal disorders with a genetic mosaicism basis, might be possible due to nonallelic twin-spotting which in the embryologic period would define an abnormal development of neural, vascular, and cutaneous structures.

Streptococcal exanthem in a blaschkolinear pattern: clinical evidence for genetic mosaicism in hypomelanosis of ito

Due to the presence of two different clones of cells in early embryogenesis, numerous congenital and acquired dermatoses have a linear distribution following the lines of Blaschko. Acquired inflammatory skin diseases are rarely observed in linear patterns. Our patient was born with macrocephaly, left eye glaucoma, and a left facial and contralateral corporal hemihypertrophy, cerebral dysgenesis, and skeletal abnormalities. Hypopigmented S-shaped linear macules on the trunk and linear streaks on the arms and legs were compatible with hypomelanosis of Ito. At 5 years of age the patient presented with an erythematous follicular exanthem compatible with scarlet fever exclusively in the lines of Blaschko. This fact suggests a genetic mosaicism.

Multiple congenital contractures: birth prevalence, etiology, and outcome

OBJECTIVES

We wanted to estimate the birth prevalence of multiple congenital contractures (MCC), determine the cause of the MCC according to the primary level of involvement of the developing motor system, and compare the different groups in terms of inheritance, mortality, and morbidity.

STUDY DESIGN

A retrospective epidemiologic study through the screening of registers, reviews of medical records, and clinical re-examinations was performed in western Sweden to identify all the children with MCC born between 1979 and 1994.

RESULTS

The birth prevalence of MCC on the basis of 68 cases was 1 in 5100 live births. The majority of cases with cerebral involvement (n = 23), spinal involvement (n = 16), or mechanical restriction (n = 3) were sporadic, whereas most cases with neuromuscular (n = 12) or connective tissue involvement (n = 9) were inherited. The cerebral group was more severely affected compared with the other groups in terms of mortality, joint contractures at birth, feeding difficulties during infancy, and independent walking at follow-up. In 8 cases with myopathy, the joint contractures were normalized on follow-up.

CONCLUSION

A search for a specific etiology in each case is important for genetic counseling, prognosis, and therapy because inheritance, mortality, and morbidity differ between the groups.

Heterochromia of the scalp hair: a result of pigmentary mosaicism?

Five patients who presented stable bands of hair of a different color with respect to the surrounding hair are reported. In 4 patients this was an isolated finding. One patient also had diffuse linear skin hypopigmentation and other abnormalities. We hypothesize that these 5 cases represent a distinct type of hair heterochromia, possibly because of somatic mosaicism for genes affecting pigmentation.

Genetic skin disorders

Neonatologists do not require a detailed knowledge of all genetic skin disorders but need to recognize one if they see it. The unique accessibility of the skin makes it possible to observe the physical signs and deduce the child's immediate needs from first principles. The morphological classification given here will help the nondermatologist establish a clinical diagnosis. Tremendous advances over the last 10 years in understanding the molecular basis of skin disease make it possible, in many cases, to confirm the diagnosis and to counsel the family accurately.

Depigmented hypertrichosis following Blaschko's lines associated with cerebral and ocular malformations: a new neurocutaneous, autosomal lethal gene syndrome from the group of epidermal naevus syndromes?

The lines of Blaschko represent one of the cutaneous patterns of mosaicism followed by various skin disorders. Developmental abnormalities affecting other tissues derived from the embryonic ectoderm and mesoderm are occasionally associated. We describe a 30-year-old man with depigmented, bilateral hypertrichosis and dilated follicular orifices following Blaschko's lines associated with cerebral and ocular malformations. The findings suggest a previously unreported neurocutaneous, autosomal lethal gene syndrome from the group of epidermal naevus syndromes.

Functional Xp disomy and hypomelanosis of Ito

BACKGROUND

Hypomelanosis of Ito (HI) is a neurocutaneous phenotype that reflects different mosaicisms, including functional imbalances secondary to chromosome-X inactivation patterns in certain X;autosome translocation carriers.

METHODS

We assessed X inactivation patterns by means of the human androgen receptor (HUMARA) assay and BrdU labeling in affected and unaffected skin of a young female with HI and a de novo t(X;13)(Xp13q;Xq13p). PCR analysis was carried out in DNA extracted from uncultured and cultured skin, whereas the BrdU replication patterns were sought in cultured fibroblasts. Parental DNA was also tested. Fluorescence in situ hybridization (FISH) with X and 13/21 centromere probes (DXZ2 and D13Z1/D21Z1) and a cosmid for the X inactivation center were also performed to refine breakpoint assignments.

RESULTS

An X inactivation pattern implying functional Xpter-->q11 disomy was found in DNA extracted from uncultured hypopigmented skin, whereas preferential inactivation of the normal X was observed in uncultured normal skin as well as in cultured fibroblasts (after one passage) from both affected and unaffected skin areas. PCR analysis also showed paternal origin of the translocation. BrdU labeling of metaphases from hypopigmented and normal skin primary cultures showed der(Xq13p) to be inactive in about 25% of the cells. FISH revealed that der(Xp13q) had a compound centromere, whereas der(Xq13p) retained 13 centromere repeats but lacked X centromere sequences. Hence, breakpoints were assigned to Xq11 and 13q10. The X inactivation center cosmid gave a signal on both normal X and der(Xp13q), indicating that the inactivation center was not disrupted by the translocation.

CONCLUSIONS

These findings confirm that mosaic functional Xp disomy, rather than disruption of X-linked genes, is associated with HI and involvement of the central nervous system (CNS) in some carriers of a structurally balanced X;autosome translocation.