Higher prevalence of X-linked ichthyosis vs. ichthyosis vulgaris in Mexico

Filaggrin mutations p.R501X and c.2282del4 in ichthyosis vulgaris

Ichthyosis vulgaris (IV) is the most common hereditary disorder of cornification in humans, characterized by generalized fine scaling of the skin, palmar hyperlinearity with or without keratosis pilaris and atopy. Recently, the molecular basis of IV was ascribed to loss-of-function mutations in the gene encoding filaggrin (FLG), namely p.R501X and c.2282del4. Homozygotes and compound heterozygotes were severely affected whereas heterozygotes showed mild disease or were asymptomatic, suggesting semidominant inheritance with incomplete penetrance in heterozygotes. We report the presence of FLG mutations in 15 out of 21 IV patients with a marked generalized scaling phenotype, including eight affected members of a four-generation family. In this group of patients not only homozygous and compound heterozygous, but also heterozygous patients for p.R501X and c.2282del4 display a pronounced phenotype, whereas in none of six individuals these two mutations were detectable despite decreased filaggrin expression on immunohistochemistry in two patients, indicating that other mutations in FLG and/or in other genes remain to be identified. In contrast, two additional p.R501X heterozygotes from the extended family are asymptomatic. In a control population from west-Austria a combined p.R501X and c.2282del4 carrier frequency of 6/110 (5.45%) was observed. We confirm that these FLG variants are common, but our results point to the existence of additional modifiers.

Clinico-epidemiological features of primary hereditary ichthyoses in the Eastern province of Saudi Arabia

BACKGROUND

A total of 10 455 new dermatology patients were seen in the dermatology clinics of King Fahad Hospital of the University (KFHU), Al-Khobar, Saudi Arabia, between January 1990 and December 1995. We identified 71 patients with a histopathologically confirmed diagnosis of specific forms of primary hereditary ichthyoses (PHI). We have reviewed the epidemiological and clinical features of these patients.

OBJECTIVE

To document the epidemiological and clinical features of patients with PHI in the Eastern Province of Saudi Arabia.

METHODS

We used the dermatology out-patient department (OPD) logbooks to identify cases of PHI from new patients presenting with different dermatological problems over a 6-year period. We used specifically designed protocol forms to extract epidemiological and clinical data from the study patients' medical records. These were entered into a computer database and analyzed using standard statistical software.

RESULTS

A total of 71 patients, 44 males and 27 females (male : female sex ratio of 1.63 : 1), were identified from a total of 10 455 new patients seen in our dermatology clinics between January 1990 and December 1995. The occurrence rate of PHI, in our clinics, was 0.67% or 7 per 1000 new dermatology cases. The clinical pattern of PHI showed that Icthyosis Vulgaris was the most common form seen, followed by Nonbullous Ichthyosiform Erythroderma. Thirty-one patients (44.7%) with Ichthyosis Vulgaris (IV) were seen: 12 patients (16.9%) with X-linked Recessive Ichthyosis (XLRI), four patients (5.6%) with Lamellar Ichthyosis (LI), three patients (4.2%) with Bullous Ichthyosiform Erythroderma (BIE) and 21 patients (29.6%) with Nonbullous Ichthyosiform Erythroderma (NBIE). There was a significantly high consanguinity rate in our patients (85%), and the family history was positive in 53 cases out of the 71 (75%).

CONCLUSIONS

This preliminary study is the first report of its kind from Saudi Arabia and documents the clinico-epidemiological features of PHI patients in the Eastern Province. The high rate of parental consanguinity among our Saudi patients may account for the high proportion of patients with a positive family history. Consanguinity also probably explains why the most severe forms of PHI were seen in a significant number of new patients' siblings. These severe forms of PHI (Nonbullous Ichthyosiform Erythroderma, Bullous Ichthyosiform Erythroderma and Lamellar Ichthyosis) together constituted nearly 40% of all cases.

Clinico-epidemiological features of congenital nonbullous ichthyosiform erythroderma in the eastern province of Saudi Arabia

BACKGROUND

A total of 10 455 new dermatology patients were seen in the dermatology clinics of King Fahd Hospital of the University (KFHU), Al-Khobar, Eastern Saudi Arabia, between January 1990 and December 1995. We identified 21 patients with a histopathologically confirmed diagnosis of congenital nonbullous ichthyosiform erythroderma (CNBIE). We have reviewed the epidemiological and clinical features of these patients.

OBJECTIVE

To document the epidemiological and clinical features of patients with CNBIE in eastern Saudi Arabia.

METHODS

We used the dermatology outpatient department (OPD) logbooks to identify diagnosed cases of CNBIE from new patients presenting with different dermatological problems over a 6-year period. We used specifically designed data-collection protocol forms to extract epidemiological and clinical data from the patients' medical records. These were entered into a computer database and analysed using standard statistical software.

RESULTS

A total of 21 patients (five males, 16 females) with a male : female ratio of 0.31 : 1 were identified from a total of 10 455 new patients seen in our dermatology clinics over the study period. The occurrence rate of CNBIE in our clinics was 0.2%, or two per 1000 new dermatology cases. Nineteen (90%) of 21 CNBIE patients were born with collodion membranes. Eighty-one per cent of our patients had a positive family history of CNBIE. Consanguinity among the parents of our CNBIE patients was significantly high at 95%.

CONCLUSIONS

To the best of our knowledge, this preliminary study is the first report of its kind from Saudi Arabia (documenting the clinico-epidemiological features of CNBIE patients in the Eastern Province). The high rate of parental consanguinity among the parents of our Saudi CNBIE patients may account for the high incidence rate of this genodermatosis in eastern Saudi Arabia. In comparison with results of other studies that reported a low occurrence rate of CNBIE among dermatology patients, our results were of a significantly higher rate.

Primary hereditary ichthyoses in the Eastern Province of Saudi Arabia

BACKGROUND

Of 10,455 new dermatology patients seen at the Dermatology Clinic of King Fahad Hospital of the University, Al-Khobar, Saudi Arabia, between January 1990 and December 1995, the epidemiologic and demographic features of 71 patients, each with a histopathologically confirmed diagnosis of one specific type of primary hereditary ichthyosis (PHI), have been reviewed.

OBJECTIVE

To study and document the epidemiologic and demographic profiles of patients with PHI in the Eastern Province of Saudi Arabia.

METHODS

From the outpatient department dermatology logbooks, 71 patients with PHI, from 10,455 new cases with different dermatologic problems seen during the 5-year period, were included in this study. Using specially designed protocol forms, epidemiologic and demographic data were extracted from the medical records of the patients, entered into a computer, and analyzed using the SPSS program.

RESULTS

Seventy-one patients with PHI, 44 males and 27 females (ratio, 1.63 : 1), were seen at our Dermatology Clinic between January 1990 and December 1995. The occurrence rate of PHI in our clinic is 0.67%, i.e. approximately 7 per 1000 new cases. The clinical pattern of PHI was as follows: 31 patients (44.7%) with ichthyosis vulgaris (IV), 12 (16.9%) with X-linked recessive ichthyosis (XLRI), four (5.6%) with lamellar ichthyosis (LI), three (4.2%) with bullous ichthyosiform erythroderma (BIE), and 21 (29.6%) with nonbullous ichthyosiform erythroderma (NBIE). IV was most common, followed by NBIE. Parental consanguinity was high (approximately 85%), and the family history was positive in 53 of the 71 cases (75%).

CONCLUSIONS

This preliminary study has attempted to document the epidemiologic patterns of PHI patients in Saudi Arabia and, to our knowledge, this is the first report of its kind in this country. We found a high rate of parental consanguinity, a high percentage of patients with a positive family history, and many siblings affected by the severest forms of PHI, namely NBIE, BIE, and LI, which accounted for 39.4% of all cases of PHI.

Frequency of X-linked ichthyosis in coastal southern Italy: a study on a representative sample of a young male population

BACKGROUND

No reports on the frequency of X-linked ichthyosis (XLI) in the Italian general population and few surveys on the frequency of XLI in large communities in the world are available.

OBJECTIVE

The aim of this study was the assessment of the frequency of XLI in a large representative sample of the Italian male population.

SUBJECTS AND METHODS

This study involved young men who enlisted as conscripts in the Italian Navy from January 1998 through February 2002, examined, prior to enlistment, at the Draft Council's Medical Unit of the Italian Navy in Taranto, Italy, to evaluate their psychophysical fitness. All the patients with an ichthyosiform condition were referred to the Department of Dermatology of the Navy Hospital, underwent a thorough dermatological examination and completed a questionnaire regarding their personal and familial history. Pertinent results of the other clinical investigations were recorded and the final diagnosis was formulated on the basis of all these data.

RESULTS

From January 1998 through February 2002, of 75,653 young men examined, 15 cases of XLI were diagnosed, with a frequency of 1:5,043 or 1.98 per 10,000 (95% confidence interval based on the Poisson distribution 1.01-2.90). Four out of 15 cases (26.6%) showed corneal opacities. No other significant associated pathological change was observed.

CONCLUSIONS

As this study is a survey involving a large male sample, homogeneous with reference to age, race and country of origin (southern Italy), the frequency of XLI could be estimated at about 1.98 per 10,000 males. These data are roughly in agreement with estimates from other European surveys.