Hypomelanosis of Ito with triphalangeal thumbs

Hypomelanosis of Ito presenting with pediatric orthopedic issues: a case report

Introduction

Hypomelanosis of Ito was originally described as a purely cutaneous disease. Extracutaneous manifestations were described later, forming a neurocutaneous syndrome including skeletal, muscular, ocular and central nervous system symptoms.

Hypomelanosis of Ito is characterized by a depigmentation along the lines of Blaschko on the trunk and extremities in certain patterns.

The aim of this article was to report another case and give an overview of the related orthopedic symptoms that have been previously described. It was also our wish to contribute with recommendations for consideration with regard to bandages on eczematous rashes, especially on clubfeet.

Case presentation

A one-and-a-half-month-old boy of Caucasian background born with talipes equinovarus, or clubfoot, on his right foot presented with an eczematous rash after surgical correction and plaster bandaging.

Conclusions

It is the appearance of hypopigmentation, either alone or in combination with a congenital malformation, particularly central nervous system or musculoskeletal anomalies, which should form the basis of a presumptive diagnosis. This should then lead to further investigations and should always include skin biopsies and a test for chromosomal mosaicism.

We report the case of a boy with a clinical picture consisting of a depigmented skin pattern, mental retardation, pes cavus, talipes equinovarus, clinodactyly, eczema, inverted cilia of the eye, strabismus, reduced hearing, ventral hernia, glomerulonephritis, missing testicles, leg length discrepancy with scoliosis, back pain and a syrinx.

It is perhaps impossible to make any conclusions about extracutaneous symptoms. However, some symptoms such as retardation, cramps and seizures, delayed development and hypotonia cannot be ignored.

Because of the possibility of creating an undesirable and long postoperative period with complications, it is very important to have this diagnosis in mind when deciding to do surgery or not if there are signs of dermatological problems before surgery. In this case, it could also be good clinical practice to test the patient’s reaction to plaster or other bandages.

Hypomelanosis of ITO. A study of 76 infantile cases

We show the complications observed in a large series of children with hypomelanosis of Ito (HI) or incontinentia pigmenti achromians, studied in a neurology service over 30 years. Of the 76 patients, 35 were male (46%) and 41 female (54%) with ages ranging from newborn to 10 years at the time of the first visit. They were thoroughly studied from the clinical, genetic, psychological, neuroradiological, with computed tomography (CT) and/or magnetic resonance imaging (MRI), and electroencephalographic (EEG) points of view. Mental retardation was observed in 43 cases (57%) of whom eight (10%) showed autistic behavior; 16 (21%) were borderline and only 17 (22%) had a normal mental level (IQ > 85). Thirty-seven patients (49%) had seizures, consisting of infantile spasms in six cases (8%). Twelve cases showed macrocephaly and coarse facies, six had microcephaly, and 14 showed hypotonia with pes valgus and genu valgus. Three cases of cerebellar hypoplasia, another of intracranial arteriovenous malformation and another of distal spinal muscular atrophy were observed as well. Some other anomalies, such as syndactyly, clinodactyly, abnormalities of the skeleton, asymmetry of the facies, ears, body and/or extremities, gynecomastia and asymmetrical breasts, short stature, oral alterations, congenital cardiopathies and genital anomalies, were also occasionally found. Three children died, but necropsy was performed only in one. Anatomical and histological studies did not disclose specific findings.

Cytogenetic and dermatoglyphic findings in a familial case of hypomelanosis of Ito (incontinentia pigmenti achromians)

Cytogenetic and dermatoglyphic investigations were performed in a mother (M.B.) and her daughter (D.B.), who were both suffering from hypomelanosis of Ito (incontinentia pigmenti achromians; HI). Whereas quite normal chromosomal results could be obtained after culture of peripheral lymphocytes, a diploid/tetraploid mosaicism (46,XX/92,XXXX) was found in cultured skin-fibroblasts derived from a hypopigmented skin area of M.B., with a slowly decreasing tetraploidy rate in the course of passaging: #2 23%, #5 11%, #11 and #14 6% and #18 and #21 2%. In cultures of normally pigmented skin, only single tetraploid cells could be detected. Dermatoglyphic examinations in both patients showed single transverse creases, a high number of secondary creases and a longitudinal alignment of the main line A bilaterally, and there was a tricentric fingertip pattern on the right digit III of M.B., i.e. a pattern which occurs very seldom in human beings. The results are discussed in respect to the clinical-diagnostic overlap of HI and incontinentia pigmenti Bloch-Sulzberger.

Skin and bones. I

Skin disorders in which a radiograph may detect associated bony changes or abnormalities of calcification are discussed. They are grouped into eight categories: (1) inherited diseases (e.g., alkaptonuria, neurofibromatosis); (2) congenital disorders (e.g., Sturge-Weber and Proteus syndromes); (3) inflammatory conditions (e.g., dermatomyositis, sarcoidosis); (4) infections (e.g., dental sinus, syphilis); (5) neoplasias (e.g., histiocytosis, mastocytosis); (6) drug- and environment-induced (e.g., acroosteolysis, retinoid toxicity); (7) calcinosis cutis; and (8) osteoma cutis. Part I of our review discusses the first two categories.

Axenfeld anomaly in association with hypomelanosis of Ito

Hypomelanosis of Ito is a rare neurocutaneous disorder with associated ocular, facial, dental and skeletal abnormalities. The authors describe a case of hypomelanosis of Ito occurring with anterior segment mesenchymal dysgenesis of the Axenfeld type. An attempt is made to explain many of the major features of hypomelanosis of Ito in terms of neural crest origin, and to classify the disease as a neurocristopathy.

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.

Chromosome mosaicism in hypomelanosis of Ito

Our finding of chromosome mosaicism with a ring 22 in a retarded black boy with hypomelanosis of Ito prompted a review of this "syndrome." Most patients have a variety of non-dermal defects, particularly those affecting CNS function. Among karyotyped patients, most are chromosome mosaics of one sort or another. Hypomelanosis of Ito turns out to be a causable non-specific phenotype, i.e., a clinical marker for chromosome mosaicism of all different types in individuals with a dark enough skin to show lighter patches. Consequently, cytogenetic evaluation is indicated in all patients with this skin finding.

Genetic counselling in hypomelanosis of Ito: case report and review

A 27-year-old male with hypomelanosis of Ito (HI) is reported. One of his two children had a postaxial ray defect of one leg but neither had cutaneous features of HI. Somatic mosaicism for a gene defect lethal to ectodermal derivatives offers the best explanation for HI in males, with consequent negligible recurrence risk. The limb defect is considered coincidental. The excess of girls with HI could be due to a female cohort with incontinentia pigmenti (IP) which may be indistinguishable: counselling of females must therefore take account of possible X-linked inheritance.

Triphalangeal thumb

Triphalangeal thumb (TPT), a rare malformation of uncertain pathogenesis, may occur as an isolated defect, in association with other malformations of the hands, or as a feature of a syndrome or sequence. Isolated TPT occurs in two functional types: opposable and non-opposable. The latter appears to be inherited as a simple autosomal dominant trait, while the former is generally sporadic. TPT is associated with a number of specific malformations of the hand or foot, several of which have a well documented autosomal dominant pattern of inheritance. TPT is a feature of a number of specific syndromes. In this setting it may be associated with radial hypoplasia, bone marrow dysfunction, congenital heart disease, lung hypoplasia or agenesis, anorectal malformations, sensorineural hearing loss, onychodystrophy, mental retardation, and other disorders. TPT serves as a useful marker in such patients; in conjunction with the clinical and radiological findings, it can help to establish the correct diagnosis, leading to appropriate management and genetic counselling.

Hypomelanosis of Ito. Neurological complications in 34 cases

We studied 34 Spanish children with hypomelanosis of Ito. This disease has an incidence of 1 per 1000 new patients consulting a paediatric neurological service, or 1 per 8000-10,000 unselected patients in a children's hospital. About 94% of our patients show noncutaneous abnormalities. Mental retardation (IQ below 70) was present in 64.7%; another 14.7% had an IQ between 70 and 90, usually associated with poor school performance. Four children exhibited autistic behaviour. Seizures of various types were present in 53% of cases. Other skin alterations in addition to the typical hypomelanosis were observed in 38% of our cases: café-au-lait spots, angiomatous nevi, nevus marmorata, nevus of Ota, Mongolian blue spot, heterochromia of the iris or hair, and other nonspecific pigmentations. Other associated disorders occur inconsistently and include macrocephaly, microcephaly, hémihypertrophy, kyphoscoliosis, coarse facial features, genital anomalies, inguinal hernia, congenital heart disease, hypertelorism, and abnormalities of the teeth, feet and eyes. Autosomal dominant inheritance is demonstrated in some but not all cases.

Hypomelanosis of Ito: neurologic complications

Hypomelanosis of Ito is an uncommon, but clinically recognizable neurocutaneous syndrome. Neurologic complications are frequent and most commonly include seizures, psychomotor delays, changes in tone, and gait disturbances. Four patients with hypomelanosis of Ito and neurologic complications are presented; one patient had an associated chromosome aberration not reported previously.

Ito's hypomelanosis (incontinentia pigmenti achromians). A review of four cases

In 1952 Ito described the occurrence of a bilateral systematized depigmented nevus in a 22-year-old Japanese woman. He used the term incontinentia pigmenti achromians. The condition has been described under various designations, such as for instance Ito's hypomelanosis. Till now 71 patients with this syndrome are described. We will report 4 cases, 2 boys and 2 girls, 2 Caucasian, 1 Indonesian and 1 Caribean child. The cutaneous signs in these 4 patients fit in with the syndrome of Ito's hypomelanosis. Of these 4 children 3 are mentally retarded, 2 have epilepsy. Congenital malformations are seen in 3 children. Electronmicroscopy of skin biopsies of the hypomelanotic nevus and of the normal skin were performed. In the biopsy of the normal skin of one patient interruption of the basement membrane is seen. Anomalies of the central nervous system as seen in our patients occur in about 40% of the cases. Abnormalities of skin derivatives next to other ectodermal anomalies are described. Affection of other germ layers also occur to a varying degree. In our 4 patients some of these abnormalities exist also. These 4 cases are presented to underline the fact that this syndrome seems not to be as extremely rare as is proposed.

Congenital cranio-facial dysmorphosis associated with Ito's syndrome (incontinentia pigmenti achromians): a case report

The authors describe a child who presented multiple congenital malformations affecting the cranio-facial region and the extremities associated with a rare skin lesion (incontinentia pigmenti achromians).

Hypomelanosis of Itô: a neurocutaneous syndrome

A 2 1/2-year-old girl with hypomelanosis of Itô is described. There is a bizarre distribution of congenital depigmentation stopping abruptly at the midline anteriorly, with whorl-like and zig-zag patterning. As can happen in this syndrome, there is severe retardation and intractible epilepsy, with computerized tomography showing gross cerebral atrophy.