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Biomedical subjects

K H Gustavson

Publications and source records attributed to K H Gustavson.

At least 19 recordsLinked to original sources
PubMed2002

Prevalence and associated impairments of mild mental retardation in six- to ten-year old children in Pakistan: a prospective study.

UNLABELLED: The aim of this study was to find the prevalence of mild mental retardation (MMR) in 6-10-y-old children in a prospectively followed cohort in Pakistan from four areas with different socioeconomic conditions. Retarded children were identified by a two-step method, comprising a household screening with the Ten Questions Screening in 649 families followed by clinical investigation and psychometric testing (WISC-R and Griffiths) of the 132 children found by the screening. The overall prevalence of MMR among 6-10-y-old children was 6.2%. The distribution of MMR was uneven, with 1.2% among children from the upper-middle class, 4.8% in the village, 6.1% in the urban slum and 10.5% in the poor periurban slum area. Additional impairments were found in 75% of the children with MMR, of which speech impairment was the most common. CONCLUSION: The prevalence of MMR was found to be higher in a developing country than in developed countries. It also seemed to be related to poor socioeconomic conditions, as the prevalence in the upper-middle class was comparable to figures from developed countries, while the prevalence in children from poor population groups was much higher.

Child↗
PubMed1999

Friedreich's ataxia: point mutations and clinical presentation of compound heterozygotes.

Friedreich's ataxia is the most common inherited ataxia. Ninety-six percent of patients are homozygous for GAA trinucleotide repeat expansions in the first intron of the frataxin gene. The remaining cases are compound heterozygotes for a GAA expansion and a frataxin point mutation. We report here the identification of 10 novel frataxin point mutations, and the detection of a previously described mutation (G130V) in two additional families. Most truncating mutations were in exon 1. All missense mutations were in the last three exons coding for the mature frataxin protein. The clinical features of 25 patients with identified frataxin point mutations were compared with those of 196 patients homozygous for the GAA expansion. A similar phenotype resulted from truncating mutations and from missense mutations in the carboxy-terminal half of mature frataxin, suggesting that they cause a comparable loss of function. In contrast, the only two missense mutations located in the amino-terminal half of mature frataxin (D122Y and G130V) cause an atypical and milder clinical presentation (early-onset spastic gait with slow disease progression, absence of dysarthria, retained or brisk tendon reflexes, and mild or no cerebellar ataxia), suggesting that they only partially affect frataxin function. The incidence of optic disk pallor was higher in compound heterozygotes than in expansion homozygotes, which might correlate with a very low residual level of normal frataxin produced from the expanded allele.

Adolescent↗
PubMed1999

Further evidence of genetic homogeneity in Sjögren-Larsson syndrome.

Sjögren-Larsson syndrome is an autosomal recessive disorder characterized by congenital ichthyosis, spastic di- or tetraplegia and mental retardation. In 1994 Sjögren-Larsson syndrome was mapped to chromosome 17, close to the genetic marker D17S805 in a study of 24 Swedish families. We have analysed 12 microsatellite markers in 10 additional non-Swedish families with Sjögren-Larsson syndrome originating from Germany, Lebanon, Spain and Canada. The results are consistent with earlier data and give further evidence of Sjogren-Larsson syndrome being a homogeneous disorder. Swedish soldiers were bivouacking in Germany during the 30-year war in the 17th century and it has been suggested that they could have introduced the Sjögren-Larsson syndrome gene to the German population. Haplotypes from 7 German families with Sjögren-Larsson syndrome were compared with earlier analysed Swedish haplotypes. No evidence of all German patients carrying the same mutation or the major "Swedish Sjögren-Larsson syndrome gene" was found.

DNA↗
PubMed1998

Clustering of private mutations in the congenital chloride diarrhea/down-regulated in adenoma gene.

An inherited defect in intestinal anion exchange, congenital chloride diarrhea (CLD), was recently shown to be caused by mutations in the down-regulated in adenoma (DRA) gene. A three base pair deletion resulting in the loss of an amino acid valine (V317del) in the predicted CLD/DRA protein was shown to be responsible for all CLD cases in a Finnish founder population. Two additional mutations, H124L and 344delT, were found in Polish CLD patients. Here, we screened for additional mutations in a set of 14 CLD families of Polish, Swedish, North American, and Finnish origin using primers that allowed mutation searches directly from genomic DNA samples. We found eight novel mutations in the CLD/DRA gene. The mutations included two transversions, one transition, one insertion, and four small deletions. Of 11 sequence alterations detected so far, nine lie clustered in three short segments that are 49 bp, 39 bp, and 65 bp in size, respectively. These short segments span only 6.7% of the total cDNA length, suggesting functional importance or mutation-prone DNA regions of the corresponding CLD/DRA protein domains.

Amino Acid Sequence↗
PubMed1998

Risk factors for mortality in young children living under various socio-economic conditions in Lahore, Pakistan: with particular reference to inbreeding.

Risk factors such as maternal age, parity, previous siblings' death, inbreeding of parents, birth weight, birth length were examined in a population-based prospective study in four population groups at different levels of urbanization in and round Lahore, Pakistan. From September 1984 to March 1995, 2967 full-term, single born infants were followed from the 5th month of gestation to 12 months of age. Logistic regression analysis showed a significant relative risk (RR) of infant death associated with parents' consanguinity (RR = 1.8), birth weight (RR = 1.8) and elder siblings' death (RR = 1.7). The risk attributed to these factors was 28, 17 and 25%, respectively. The number of lethal equivalents per gamete is about one. The B/A ratio 10.36 suggests that the genetic load is likely to be mutational. In countries like Pakistan, where consanguinity is favourably practiced, a substantial proportion of infant deaths may be prevented by cessation of such marriages. The implications of this finding for the Pakistani community are discussed.

Adolescent↗
PubMed1997

Identification of mutations in the CACNL1A3 gene in 13 families of Scandinavian origin having hypokalemic periodic paralysis and evidence of a founder effect in Danish families.

Familial hypokalemic periodic paralysis (hypoPP) is an autosomal dominant disorder characterised by episodic attacks of paralysis of varying severity. Recently, linkage was found to markers in 1q31-32 and to the gene encoding the muscle DHP-sensitive calcium channel alpha 1-subunit (CACNL1A3). Subsequently, three mutations in this gene were identified in patients with hypoPP: Arg528His, Arg1239His and Arg1239Gly. In this study, two different mutations were found in the CACNL1A3 gene in 13 Scandinavian families, 10 of whom have the Arg528His mutation while 3 families have the Arg1239His. Furthermore, there is evidence of a founder effect in 8 of the 9 Danish hypoPP families investigated, consisting of haplotypes of microsatellite markers close to and within the CACNL1A3 gene and of the geographic origin of the families. For the first time, reduced penetrance in males with the Arg528His mutation was found in several cases.

Adolescent↗