Biomedical subjects

J T Leisti

Publications and source records attributed to J T Leisti.

4 recordsLinked to original sources

PubMed1998

Epidemiology of moderate to profound childhood hearing impairments in northern Finland. Any changes in ten years?

The epidemiology of childhood hearing impairments was studied in a clinical series of the birth cohorts for 1973-82 and 1983-92 from a geographically well-defined area. The overall prevalence of hearing impairments with PTA0.5-4 kHz > or = 40 dB was 1.2/1000 live births. Even in the later cohort, the median age ascertainment was 2.6 years for the congenital or early acquired group and 3.0 years for all impairments. Risk indicators for hearing impairment were present in half of the children, and those referred for the risk were ascertained at the median age of 1.1 years. The delay from suspicion to ascertainment was over a year in about one fifth of cases, while the median time from referral to ascertainment was only 1.8 months. The planning and implementation of neonatal hearing screening are suggested, and general information is given on paedoaudiology for both parents and professionals. A database could be beneficial in increasing the systemacy of the diagnostic process.

Child↗

PubMed1975

Human X-autosome translocations: differential inactivation of the X chromosome in a kindred with an X-9 translocation.

A kindred with an X-autosome translocation and differential inactivation of the X chromosome is described. The phenotypically normal mother has a reciprocal translocation [46,X,rcp(X;9) (q11;q32)] while the daughter's karyotype is unbalanced [46,X,--X,+der(9),rcp(X;9) (q11;q32)mat], indicating adjacent-two type of segregation in the mother. In the mother's cells the normal X is late replicating, while in the daughter's cells almost the entire der(9) is late replicating, indicating the presence of autosomal inactivation. The daughter's abnormal phenotype can be explained by her sex chromosomal complement and the absence of effective trisomy 9. At this stage there is no simple explanation to account for all types of inactivation patterns encountered in the 14 balanced and 15 unbalanced cases of X-autosome translocations reported to date. Selection of X inactivation is not an inherent characteristic of the X chromosome per se, and it is not dependent on the direction of chromosomal exchange, as was suggested previously. Correlation of the phenotypic and cytogenetic features of these patients suggests a pattern of X and autosomal inactivation consistent with the least amount of genotypic and phenotypic imbalance in most cases. The data are most consistent with random X inactivation followed by selection of the most viable cell line.

Adolescent↗

PubMed1974

The phenotype of human triploidy.

Triploid infants are born prematurely and usually live less than one day. The triploidy syndrome is characterized by general dysmaturity and the following features: muscular hypotonia; large placenta with frequent hydatidiform changes; large posterior fontanel; low-set dysmorphic auricles; hypertelorism; microphthalmia and colobomata; cutaneous syndactyly of fingers three and four; simian crease; maldeveloped external genitalia; hypospadias; cryptorchidism and Leydigian cell hyperplasia of the testes in XXY males and hypoplastic adrenals.

Abnormalities, Multiple↗

PubMedDate not supplied

Mesomelic skeletal dysplasias.

Mesomelic shortening of the extremities lends itself as a useful clinical and/or radiologic sign to characterize a group of hereditary bone dysplasias. Table 1 and Figure 4 are presented to facilitate the comparison between the many different types of mesomelic dwarfism. Differential diagnosis between these types is not difficult because of the specific bone changes and extraskeletal malformations present. As in many hereditary syndromes, however, there may be wide clinical variability within a single entity, and meticulous clinical and radiologic examination must be done to arrive at the correct diagnosis. Certain other forms of chondrodystrophies, such as achondroplasia, hypochondroplasia, pseudoachondroplasia and distrophic dwarfism, can be easily differentiated from the mesomelic dysplasias by their clinical features and skeletal radiographs. Nothing is known about the pathogenesis of the various forms of mesomelic dysplasias. There is no available specific treatment, although corrective surgery has benefited selected patients. The correct diagnosis is, however, important both for prognostication and accurate genetic counseling.

Adolescent↗