Ictiosis sindrómicas / Syndromic ichthyosis

Las ictiosis hereditarias son un grupo de desórdenes mendelianos, con manifestaciones clínicas y alteraciones genéticas heterogéneas caracterizadas por la presencia de escamas y/o hiperqueratosis. Las ictiosis sindrómicas son aquellas en las que el defecto genético se manifiesta en la piel y también en otros órganos. Presentamos 7 pacientes con ictiosis sindrómicas: un síndrome IFAP (ictiosis folicular, atriquia, fotofobia), un síndrome de Conradi-Hünermann-Happle (CHH), dos síndromes de Netherton (SN), dos síndromes de Sjögren-Larsson (SSL) y un síndrome KID (queratitis, ictiosis, sordera). Se analizan las características clínicas y diagnósticas de nuestros pacientes (AU)

Inherited ichthyosis are a group of clinical and genetic heterogeneous disorders characterized by the presence of scales, hyperkeratosis or both. In syndromic ichthyosis, the genetic defect involves the skin and other organs. We present 7 patients with syndromic ichthyosis: a case of IFAP syndrome (ichthyosis follicularis with alopecia and photophobia), a case of Conradi-Hünermann-Happle (CHH) syndrome, two cases of Netherton syndrome, two cases of Sjögren-Larsson syndrome and a case of KID syndrome (keratitis, ichthyosis and deafness). We analyze the diagnostic and clinical features of our patients (AU)

Atypical X-linked ichthyosis in a patient with a large deletion involving the steroid sulfatase (STS) gene.

A 70-year-old male presented with very large, thick, tightly adherent, dark-brown scales on the front of his lower extremities. His face, neck, back, abdomen, upper extremities, flexural areas, palms and soles as well as hair and nails were not involved. Family history was negative for similar lesions. Otherwise, the patient had a normal development. Onset of symptoms occurred during childhood with scales on lower extremities with no more additional features. Treatment included emollients exclusively with partial and temporary remission of cutaneous lesions. Recently, the patient had not received topical or systemic medical treatment. Laboratory investigations were within normal limits. The patient had undetectable levels of STS activity when compared with normal control (0.00 pmol mg(-1) protein h(-1)) which confirmed the diagnosis of X-linked ichthyosis (XLI) . PCR analysis showed deletion of the STS gene, markers DXS1139 and DXF22S1and the 5' end of the VCX3A gene. The patient had scales present on lower extremities only with no medical treatment that corresponded to an unusual clinical manifestation of XLI. Clinical manifestations of XLI are due to a great variety of environmental, genetic and individual factors that should be considered in XLI diagnosis.

Segregation analysis in X-linked ichthyosis: paternal transmission of the affected X-chromosome.

BACKGROUND: Steroid sulphatase (STS) deficiency has been described in a diversity of ethnic populations. The phenotype of STS deficiency, X-linked ichthyosis (XLI), is a genodermatosis characterized by dark scaly skin. About 90% of patients with XLI have complete deletion of the entire STS gene and flanking sequences. The variable number tandem repeats, on either side of the STS gene, appear to play an important role in these interstitial deletions due to nonallelic homologous recombination (NAHR). It is difficult to establish if this NAHR occurs between two chromosomes, between sister chromatids or between the same chromatid. OBJECTIVES: To identify the parental origin of the affected X-chromosome in seven unrelated sporadic cases of XLI. METHODS: Amplification of the regions from DXS89 to DXS1134 (telomeric-centromeric) including the 5' and 3' ends of the STS gene was performed through polymerase chain reaction. GeneScan analysis was performed using the DXS987, DXS8051 and DXS1060 markers located on the short arm of the X-chromosome. Fluorescence in situ hybridization analysis was performed with a digoxigenin-labelled cDNA STS probe. RESULTS: STS gene deletion in patients with XLI involved the sequences DXS1139 and DXF22S1. In five families segregation analysis showed paternal transmission of the affected X-chromosome in the XLI carrier. It was not possible to determine the parental origin of the affected X-chromosome in two families. CONCLUSIONS: These data strongly suggest that STS gene deletion occurred in the male meiosis probably due to an intrachromosomal event, recombination between S232 sequences on the same DNA molecule, or during the process of DNA replication.

Analysis of the VCX3A, VCX2 and VCX3B genes shows that VCX3A gene deletion is not sufficient to result in mental retardation in X-linked ichthyosis.

BACKGROUND: X-linked ichthyosis (XLI), an inborn error of metabolism, is due to steroid sulphatase (STS) deficiency. Most patients with XLI harbour complete deletion of the STS gene and flanking sequences. The presence of low copy number repeats on either side of the STS gene seems to have a major role in the high frequency of these deletions. Some patients with XLI with terminal deletions of Xp22.3 involving marker DXS1139 and the STS gene show mental retardation (MR); VCX3A is the only gene located on this critical region. OBJECTIVES: To analyse the VCX3A, VCX, VCX2 and VCX3B genes in 80 unrelated Mexican patients with XLI with normal intelligence. METHODS: STS activity was measured in the leucocytes using 7-[3H]-dehydroepiandrosterone sulphate as a substrate. Amplification of the regions from telomeric DXS89 to centromeric DXS1134 including both extremes of the STS and the VCX3A, VCX, VCX2 and VCX3B genes was performed using polymerase chain reaction. RESULTS: No STS activity was detected in the patients with XLI (0.00 pmol mg(-1) protein h(-1)). We observed two different deletion patterns: the first group included 62 patients with deletion of VCX3A and VCX genes. The second group included 18 patients with breakpoints at several regions on either side of the STS gene not including the VCX3A gene. CONCLUSIONS: These data indicate that more complex mechanisms, apart from possible VCX3A gene participation, are occurring in the genesis of MR in XLI, at least in the sample of Mexican patients analysed.

Ictiosis ligada al cromosoma X: comunicación de tres casos y revisión de la literatura / X-linked ictiosis: report of 3 cases and review of the literature

La ictiosis ligada al cromosoma X es una genodermatosis poco frecuente que afecta a varones a partir de las 2 semanas de vida y se caracteriza por xerodermia, hiperqueratosis, descamación y, en algunos casos, manifestaciones extracutáneas como criptorquidia y opacidad de la córnea. La enfermedad es de evolución crónica y experimenta mejoría parcial en época estival. La deleción total o parcial de la enzima sulfatasa esteroidea es la causa de las manifestaciones clínicas. Presentamos tres pacientes con ictiosis ligada al cromosoma X, a quienes se les realizaron interconsultas con los servicio de Oftalmología y Pediatría. Se encuentran actualmente en tratamiento con emolientes...

Recessive X-linked ichthyosis associated with hypertrophic pyloric stenosis: a chance occurrence?

The association of recessive X-linked ichthyosis (RXLI) and hypertrophic pyloric stenosis (HPS) has been considered to be due to a probable contiguous gene defect. However, there are several reports of patients with large deletions on both sides of the steroid sulphatase gene (responsible for RXL1) that show no signs of HPS. We report the third pedigree wherein RXL1 was associated with HPS. Apart from the proband, both diseases showed themselves as independent events in the family tree with ichthyosis present in two other individuals and HPS in three other relatives. We calculated the probability that both diseases occurred simultaneously in the index case as a chance occurrence as 1 : 40 (using the Independence principle of probability). We conclude that in our pedigree it is likely that these two rare diseases show an accidental and not a true genetic association.

IFAP syndrome "plus" seizures, mental retardation, and callosal hypoplasia.

Ichthyosis follicularis, congenital alopecia, and photophobia are typical features of a rare X-linked recessive disorder termed ichthyosis follicularis with atrichia and photophobia syndrome. A 3-year-old male with these findings and severe growth failure, mental retardation, generalized seizures, vascularizing keratitis, nail anomalies, inguinal hernia, and a normal chromosome constitution is presented. Two maternal male relatives were affected by the same condition. Magnetic resonance imaging revealed corpus callosum hypoplasia not described at present. Syndromes with alopecia, seizures, and mental retardation are analyzed on the basis of genetic and clinical results.

Deletion of exons 1-5 of the STS gene causing X-linked ichthyosis.

X-linked ichthyosis is an inherited disorder due to steroid sulfatase deficiency. It is clinically characterized by dark, adhesive, and regular scales of the skin. Most X-linked ichthyosis patients present large deletions of the STS gene and flanking markers; a minority show a point mutation or partial deletion of the STS gene. In this study we analyzed the STS gene in a family with simultaneous occurrence of X-linked ichthyosis and ichthyosis vulgaris. X-linked ichthyosis diagnosis was confirmed through steroid sulfatase assay in leukocytes using 7-[3H]-dehydroepiandrosterone sulfate as a substrate. Exons 1, 2, 5, and 6-10, and the 5' flanking markers DXS1130, DXS1139, and DXS996 of the STS gene were analyzed by polymerase chain reaction. X-linked ichthyosis patients of the family (n = 4 males) had undetectable levels of STS activity (0.00 pmol per mg protein per h). The DNA analysis showed that only exons 6-10 and the 5' flanking markers of the STS gene were present. We report the first partial deletion of the STS gene spanning exons 1-5 in X-linked ichthyosis patients.

Deletion pattern of the STS gene in X-linked ichthyosis in a Mexican population.

BACKGROUND: X-linked ichthyosis (XLI) is an inherited disorder due to steroid sulfatase deficiency (STS). Most XLI patients (>90%) have complete deletion of the STS gene and flanking sequences. The presence of low copy number repeats (G1.3 and CRI-S232) on either side of the STS gene seems to play a role in the high frequency of these interstitial deletions. In the present study, we analyzed 80 Mexican patients with XLI and complete deletion of the STS gene. MATERIALS AND METHODS: STS activity was measured in the leukocytes using 7-[(3)H]-dehydroepiandrosterone sulfate as a substrate. Amplification of the regions telomeric-DXS89, DXS996, DXS1139, DXS1130, 5' STS, 3' STS, DXS1131, DXS1133, DXS237, DXS1132, DXF22S1, DXS278, DXS1134-centromeric was performed through PCR. RESULTS: No STS activity was detected in the XLI patients (0.00 pmoles/mg protein/h). We observed 3 different patterns of deletion. The first two groups included 25 and 32 patients, respectively, in which homologous sequences were involved. These subjects showed the 5' STS deletion at the sequence DXS1139, corresponding to the probe CRI-S232A2. The group of 32 patients presented the 3' STS rupture site at the sequence DXF22S1 (probe G1.3) and the remaining 25 patients had the 3' STS breakpoint at the sequence DXS278 (probe CRI-S232B2). The third group included 23 patients with the breakpoints at several regions on either side of the STS gene. No implication of the homologous sequences were observed in this group. CONCLUSION: These data indicate that more complex mechanisms, apart from homologous recombination, are occurring in the genesis of the breakpoints of the STS gene of XLI Mexican patients.

Mutation report: a novel partial deletion of exons 2-10 of the STS gene in recessive X-linked ichthyosis.

X-linked ichthyosis is an inherited disease due to steroid sulfatase deficiency. Onset is at birth or early after birth with dark, regular, and adherent scales of skin. Approximately 85%-90% of X-linked ichthyosis patients have large deletions of the STS gene and flanking sequences. Three patients have been identified with partial deletions of the gene. Two deletions have been found at the 3' extreme and the other one implicating exons 2-5. This study describes a novel partial deletion of the STS gene in an X-linked ichthyosis patient. The subject was classified through steroid sulfatase assay in leukocytes using 7-[3H]-dehydroepiandrosterone sulfate as a substrate. Exons 1, 2, 5, and 7-10, and 3' flanking sequences DXS1131, DXS1133, DXS237, DXS1132, DXF22S1, and DXS278 of the STS gene were analyzed through polymerase chain reaction. The DNA analysis showed that exon 1 and 3' flanking sequences from DXS237 to DXS278 were present. In this study we report the fourth partial deletion of the STS gene and the first spanning exons 2-10 in X-linked ichthyosis patients.

Most "sporadic" cases of X-linked ichthyosis are not de novo mutations.

X-linked ichthyosis is an inherited disease with dark, regular and adherent scales as clinical characteristics. It is caused by a deficiency of the steroid sulphatase enzyme. Steroid sulphatase assay is a relative easy tool that enables correct diagnosis of X-linked ichthyosis patients and carriers. A large number of X-linked ichthyosis patients correspond to non-familial cases that seem to represent de novo mutations. In this study, we examined the X-linked ichthyosis carrier state of the mothers of 42 non-familial cases to determine whether their children corresponded to de novo mutations. To classify patients and carriers, a steroid sulphatase assay was performed in leukocytes using 7-[3H]-dehydroepiandrosterone sulphate as substrate. In 36 mothers (85%) we found steroid sulphatase activity compatible with the carrier state of X-linked ichthyosis. This data suggest that most of the mothers of these patients present the primary gene defect, excluding de novo mutations in the patients.

Steroid sulfatase activity in leukocytes: a comparative study in 45,X; 46,Xi(Xq) and carriers of steroid sulfatase deficiency.

The enzyme steroid sulfatase (STS) hydrolyses 3-beta-hydroxysteroid sulfates. The female-male STS activity ratio is 1.04-1.7:1 in several cell lines in adults and reaches 2:1 in prepubertal subjects. In fibroblasts, STS values in X-chromosome abnormalities show a partial positive correlation according to the number of X-chromosomes. X-linked ichthyosis (XLI) carriers, with only one copy of the STS gene, present lower STS levels than normal controls. This study analyzes the STS activity in leukocytes of 46,Xi(Xq); 45,X; XLI carriers and normal controls using 7-[3H]-dehydroepiandrosterone sulfate as substrate. X-monosomy (1.07 +/- 0.18 pmol/mg protein/h), Xq isochromosome (1.02 +/- 0.12 pmol/mg protein/h) and normal females (1.03 +/- 0.11 pmol/mg protein/h) had similar STS values (p > 0.05). XLI-carriers and males showed the lowest STS levels (0.34 +/- 0.04 pmol/mg protein/h, p < 0.001 and 0.82 +/- 0.14 pmol/mg protein/h, p < 0.05, respectively). Female-male STS activity ratio in leukocytes was 1.3:1. These data indicate that a complex mechanism regulates the STS expression depending on each type of cell line.

Ictiosis X y embarazo: reporte de un caso y revisión de la literatura / Ictiosis X and pregnancy: case report and review of literature

Se presenta el caso de una paciente de 28 años de edad, portadora de Ictiosis X recesiva, con antecedentes en embarazos anteriores de dos muertes fetales de sexo masculino, quien lleva a término un cuarto embarazo sin complicaciones y se obtiene un recién nacido femenino no afecto de la enfermedad

X-linked ichthyosis in Mexico: high frequency of deletions in the steroid sulfatase encoding gene.

The present study analyzes the frequency of molecular deletions in the steroid sulfatase (STS) encoding gene in a sample of 50 Mexican subjects with biochemical diagnosis of X-linked ichthyosis (XLI). To establish the correct diagnosis, STS activity was determined in leukocytes using 7-(3)H-dehydroepiandrosterone sulfate as the substrate. No amplification of the 3' and 5' ends of the STS gene by PCR was detected in the DNA of 49 patients, whereas only one sample of 50 presented a normal amplification. This report shows a very high frequency of deletions in the human STS encoding gene in a representative sample of the Mexican population, and it defines the characteristics of XLI in patients whose STS gene has a complete deletion as a major molecular defect.

Arilsulfatase C e o diagnóstico de ictiose recessiva ligada ao X / Arylsulphatase C and the diagnosis of recessive X-linked ichthyosis

Nas ictioses recessivas ligadas ao x (IRLX) ocorre deficiência ou ausência de atividade da enzima colesterol-sulfatase (arilsulfatase C). A descamaçäo da camada córnea é retardada, determinando quadro clínico característico. Com base em um caso clínico de IRLX, säo discutidos os aspectos clínicos, bioquímicos e genéticos dessa forma de ictiose