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I Kaitila

Publications and source records attributed to I Kaitila.

At least 37 records · Page 2Linked to original sources
PubMed1999

Integrated high-resolution BAC, P1, and transcript map of the CHH region in chromosome 9p13.

A bacterial artificial chromosome (BAC) and P1 contig of the proximal part of chromosome 9p centromeric of markers D9S165 and D9S304 is described. This 1.1- to 1.7-Mb portion of chromosome 9p13 was previously not physically mapped. It contains 24 genes or expressed sequence tags, five polymorphic AC repeats, and three new polymorphic single-strand conformation polymorphism variants. Several of the genes thus mapped are excellent candidates for disease-causing genes whose loci have previously been assigned to proximal 9p. Our primary interest is in the cartilage-hair hypoplasia gene (CHH) that resides within the contig between markers D9S163 and D9S1791 based on linkage evidence.

Base Sequence↗
PubMed1999

Increased incidence of cancer in patients with cartilage-hair hypoplasia.

OBJECTIVE: Previous reports have suggested an increased risk of cancer among patients with cartilage-hair hypoplasia (CHH). This study was carried out to further evaluate this risk among patients with CHH and their first-degree relatives. STUDY DESIGN: One hundred twenty-two patients with CHH were identified through 2 countrywide epidemiologic surveys in 1974 and in 1986. Their parents and nonaffected siblings were identified through the Population Register Center. This cohort underwent follow-up for cancer incidence through the Finnish Cancer Registry to the end of 1995. RESULTS: A statistically significant excess risk of cancer was seen among the patients with CHH (standardized incidence ratio 6.9, 95% confidence interval 2.3 to 16), which was mainly attributable to non-Hodgkin's lymphoma (standardized incidence ratio 90, 95% confidence interval 18 to 264). In addition, a significant excess risk of basal cell carcinoma was seen (standardized incidence ratio 35, 95% confidence interval 7.2 to 102). The cancer incidence among the siblings or the parents did not differ from the average cancer incidence in the Finnish population. CONCLUSIONS: This study confirms an increased risk of cancer, especially non-Hodgkin's lymphoma, probably attributable to defective immunity, among patients with CHH.

Adolescent↗
PubMed1999

Identification of the Finnish founder mutation for diastrophic dysplasia (DTD).

Diastrophic dysplasia (DTD) is especially prevalent in Finland and the existence of a founder mutation has been previously inferred from the fact that 95% of Finnish DTD chromosomes have a rare ancestral haplotype found in only 4% of Finnish control chromosomes. Here we report the identification of the Finnish founder mutation as a GT-> GC transition (c.-26 + 2T > C) in the splice donor site of a previously undescribed 5'-untranslated exon of the diastrophic dysplasia sulfate transporter gene (DTDST); the mutation acts by severely reducing mRNA levels. Among 84 DTD families in Finland, patients carried two copies of the mutation in 69 families, one copy in 14 families, and no copies in one family. Roughly 90% of Finnish DTD chromosomes thus carry the splice-site mutation, which we have designated DTDST(Fin). Unexpectedly, we found that nine of the DTD chromosomes having the apparently ancestral haplotype did not carry DTDST(Fin), but rather two other mutations. Eight such chromosomes had an R279W mutation and one had a V340del deletion. We consider the possible implications of presence of multiple DTD mutations on this rare haplotype.

Anion Transport Proteins↗
PubMed1999

Recurrence of Marfan syndrome as a result of parental germ-line mosaicism for an FBN1 mutation.

Mutations in the FBN1 gene cause Marfan syndrome (MFS), a dominantly inherited connective tissue disease. Almost all the identified FBN1mutations have been family specific, and the rate of new mutations is high. We report here a de novo FBN1mutation that was identified in two sisters with MFS born to clinically unaffected parents. The paternity and maternity were unequivocally confirmed by genotyping. Although one of the parents had to be an obligatory carrier for the mutation, we could not detect the mutation in the leukocyte DNA of either parent. To identify which parent was a mosaic for the mutation we analyzed several tissues from both parents, with a quantitative and sensitive solid-phase minisequencing method. The mutation was not, however, detectable in any of the analyzed tissues. Although the mutation could not be identified in a sperm sample from the father or in samples of multiple tissue from the mother, we concluded that the mother was the likely mosaic parent and that the mutation must have occurred during the early development of her germ-line cells. Mosaicism confined to germ-line cells has rarely been reported, and this report of mosaicism for the FBN1 mutation in MFS represents an important case, in light of the evaluation of the recurrence risk in genetic counseling of families with MFS.

Adult↗
PubMed1999

Splicing mutations of 54-bp exons in the COL11A1 gene cause Marshall syndrome, but other mutations cause overlapping Marshall/Stickler phenotypes.

Stickler and Marshall syndromes are dominantly inherited chondrodysplasias characterized by midfacial hypoplasia, high myopia, and sensorineural-hearing deficit. Since the characteristics of these syndromes overlap, it has been argued whether they are distinct entities or different manifestations of a single syndrome. Several mutations causing Stickler syndrome have been found in the COL2A1 gene, and one mutation causing Stickler syndrome and one causing Marshall syndrome have been detected in the COL11A1 gene. We characterize here the genomic structure of the COL11A1 gene. Screening of patients with Stickler, Stickler-like, or Marshall syndrome pointed to 23 novel mutations. Genotypic-phenotypic comparison revealed an association between the Marshall syndrome phenotype and splicing mutations of 54-bp exons in the C-terminal region of the COL11A1 gene. Null-allele mutations in the COL2A1 gene led to a typical phenotype of Stickler syndrome. Some patients, however, presented with phenotypes of both Marshall and Stickler syndromes.

Abnormalities, Multiple↗
PubMed1998

Autoimmune enteropathy in Schimke immunoosseous dysplasia.

The clinical phenotype of Schimke immunoosseous dysplasia (SID) is characterized by growth retardation, renal failure, recurrent infections, cerebral infarcts, and skin pigmentation beginning in childhood. We report here on a 4-year-old male child who had all characteristic symptoms of SID, and, in addition, vomiting and prolonged diarrhea. The study results suggest that malabsorption, demonstrated as increased serum immunoglobulin A anti-gliadin antibody, steatorrhea and partial villous atrophy of the jejunal small bowel, is a previously unrecognized feature of SID.

Autoimmune Diseases↗
PubMed1998

A novel splice site mutation of the EXT2 gene in a Finnish hereditary multiple exostoses family. Mutations in brief no. 197. Online.

Hereditary multiple exostoses is a dominantly inherited disease characterized by multiple benign osteochondromas. The affected individuals have an increased risk of developing sarcoma. A large Finnish family with hereditary multiple exostosis was analyzed to find the disease-causing mutation. Blood samples were obtained from 35 family members, including 21 affected and 14 unaffected individuals. Using 2-point linkage analysis the EXT phenotype was shown to be linked to the recently cloned EXT2 gene on chromosome 11p11. The coding region of the gene was sequenced and a previously unreported splice site mutation found. This G to T transversion within a 5-prime splice donor site following exon 6 was shown to cause aberrant splicing of RNA. The described change is considered to be a novel disease-causing mutation in the EXT2 gene.

Alternative Splicing↗
PubMed1998

Health-related quality of life of patients with genetic skeletal dysplasias.

UNLABELLED: While medical knowledge on genetic skeletal dysplasias has expanded, very little is known about the patients' health-related quality of life (HRQOL). To test the validity and sensitivity of the fifteen and sixteen dimensional measures of HRQOL in patients with chondrodysplasias, we examined 121 adults aged 16-54 and 19 adolescents aged 12-15 with achondroplasia, cartilage-hair hypoplasia and diastrophic dysplasia. The age and sex standardized overall HRQOL score of the adult patients (0.885 on a scale from 0 to 1) was significantly lower than that of normal controls (0.928) (P < 0.001). The difference in the HRQOL between the patients and the controls consisted mainly of the differences in dimensions of mobility, usual activities, sexual activity and discomfort, for which the patients reported a significantly lower status (more problems) than the controls (P < 0.001). Adolescent patients demonstrated HRQOL profiles similar to those of adults. However, age-specific problems occurred on the dimensions of school and hobbies, friends and physical appearance (P < 0.05). In a detailed examination of different patient groups, some clinically unexpected findings were observed, suggesting that denial is at least in part involved. CONCLUSION: Subjective assessment of HRQOL of patients with chondrodysplasias is valuable for provision of optimal care. In treatment and management special attention should be paid to those dimensions on which the patients' perceived status is currently suboptimal, especially during adolescence which probably is the most critical period in the lives of these individuals.

Adolescent↗
PubMed1998

Susceptibility to infections and in vitro immune functions in cartilage-hair hypoplasia.

UNLABELLED: Cartilage-hair hypoplasia (CHH), an autosomal recessive chondrodysplasia, results in severe growth failure, sparse hair and impaired cellular immunity. Lymphocyte subpopulations and proliferative responsiveness in mitogen stimulation were analysed in 35 patients of whom 31% had an increased incidence of infections the year prior to the evaluation. Of the patients, 57% had a decreased CD4+ cell count which led to a decreased total count of T-lymphocytes in 52% and a subnormal CD4 +/CD8 + cell ratio in 32%. The B-lymphocyte count was usually normal. The natural killer cell count was above reference values in 40% of the patients. The lymphocyte stimulation indices as studied with phytohaemagglutinin , Concanavalin A and pokeweed mitogen were subnormal in 69%, 69% and 83% of the patients, respectively. The numbers of lymphocytes, T-lymphocytes and CD4+ cells, and the pokeweed mitogen stimulation index. but not the other measured parameters, correlated significantly with the proness to infections during the preceding year. However, the correlation was reverse with higher counts in the patients who had had recurring infections. The observed significant correlations may reflect immunological stimuli caused by recurring infections. CONCLUSION: The presently used parameters of cellular immunity poorly predict the clinical outcome of an individual cartilage-hair hypoplasia patient. All patients, irrespective of their in vitro immunological competence, have to be carefully followed because of possibility of serious infections and malignancies.

Antigens, Surface↗
PubMed1998

Proteoglycan sulfation in cartilage and cell cultures from patients with sulfate transporter chondrodysplasias: relationship to clinical severity and indications on the role of intracellular sulfate production.

Mutations in the diastrophic dysplasia sulfate transporter (DTDST) gene have been associated with a family of chondrodysplasias that includes diastrophic dysplasia (DTD), atelosteogenesis type 2 (AO2) and the lethal condition achondrogenesis type 1B (ACG1B). There is a correlation between the nature of the mutations and the clinical phenotype, but our understanding of the pathophysiology of the disorder, which involves defective sulfation of cartilage proteoglycans, is far from complete. To evaluate the degree of proteoglycan undersulfation in vivo, we have extracted chondroitin sulfate proteoglycans from cartilage of twelve patients with sulfate transporter chondrodysplasias and analyzed their disaccharide composition by HPLC after digestion with chondroitinase ABC. The amount of non-sulfated disaccharide was elevated in patients' samples (controls, 5.5%+/-2.8 (n=10); patients, 11% to 77%), the highest amount being present in ACG1B patients, indicating that undersulfation of chondroitin sulfate proteoglycans occurs in cartilage in vivo and is correlated with the clinical severity. To investigate further the biochemical mechanisms responsible for the translation of genotype to phenotype, we have studied fibroblast cultures of patients with DTD, AO2 and ACG1B, and controls, by double-labelling with [35S]sulfate and [3H]glucosamine. The incorporation of extracellular sulfate, estimated by the 35S/3H ratio in proteoglycans, was reduced in all patients' cells, with ACG1B cells showing the lowest values. However, disaccharide analysis of chondroitin sulfate proteoglycans showed that these were normally sul fated or only moderately undersulfated; marked undersulfation was observed only after addition of the artificial glycosaminoglycan-chain initiator, beta-D-xyloside, to the culture medium. These results suggest that, while utilization of extracellular sulfate is impaired, fibroblasts can replenish their intracellular sulfate pool by oxidizing sulfur-containing compounds (such as cysteine) and thus partially rescue PG sulfation under basal conditions. This rescue pathway becomes insufficient when GAG synthesis rate is stimulated by beta-D-xyloside. These findings may explain why phenotypic consequences of DTDST mutations are restricted to cartilage, a tissue with high GAG synthesis rate and poor vascular supply, and imply that pharmacological therapy aimed at restoring the intracellular sulfate pool might improve PG sulfation in DTD and related disorders.

Anion Transport Proteins↗
PubMed1998

Mutations in fibroblast growth-factor receptor 3 in sporadic cases of achondroplasia occur exclusively on the paternally derived chromosome.

More than 97% of achondroplasia cases are caused by one of two mutations (G1138A and G1138C) in the fibroblast growth factor receptor 3 (FGFR3) gene, which results in a specific amino acid substitution, G380R. Sporadic cases of achondroplasia have been associated with advanced paternal age, suggesting that these mutations occur preferentially during spermatogenesis. We have determined the parental origin of the achondroplasia mutation in 40 sporadic cases. Three distinct 1-bp polymorphisms were identified in the FGFR3 gene, within close proximity to the achondroplasia mutation site. Ninety-nine families, each with a sporadic case of achondroplasia in a child, were analyzed in this study. In this population, the achondroplasia mutation occurred on the paternal chromosome in all 40 cases in which parental origin was unambiguous. This observation is consistent with the clinical observation of advanced paternal age resulting in new cases of achondroplasia and suggests that factors influencing DNA replication or repair during spermatogenesis, but not during oogenesis, may predispose to the occurrence of the G1138 FGFR3 mutations.

Achondroplasia↗
PubMed1998

Mutation analysis of LMX1B gene in nail-patella syndrome patients.

Nail-patella syndrome (NPS), a pleiotropic disorder exhibiting autosomal dominant inheritance, has been studied for >100 years. Recent evidence shows that NPS is the result of mutations in the LIM-homeodomain gene LMX1B. To determine whether specific LMX1B mutations are associated with different aspects of the NPS phenotype, we screened a cohort of 41 NPS families for LMX1B mutations. A total of 25 mutations were identified in 37 families. The nature of the mutations supports the hypothesis that NPS is the result of haploinsufficiency for LMX1B. There was no evidence of correlation between aspects of the NPS phenotype and specific mutations.

Animals↗
PubMed1998

The gene defective in anhidrotic ectodermal dysplasia is expressed in the developing epithelium, neuroectoderm, thymus, and bone.

Anhidrotic ectodermal dysplasia (EDA) is characterized by defects in the development of teeth, hair, and sweat glands. To study the expression of the human gene defective in EDA in human fetal development (Weeks 6-23 of gestational age) and in adult tissues, in situ hybridization and immunohistochemistry were used. First signs of expression were detected at Week 8 in epidermis and in neuroectodermal cells. Starting at Week 12, osteoblasts and thymus were positive for EDA mRNA. Hair follicles expressed EDA mRNA from 18 weeks. The presence of the EDA protein coincided with mRNA expression in the tissues examined. The expression pattern of the EDA gene is consistent with typical involvement of the skin in the syndrome. However, the expression is not limited to the ectodermal tissues and many sites of expression are not obviously reflected in the clinical features of the syndrome.

Adult↗
PubMed1998

Development of the hip in diastrophic dysplasia.

We examined 50 patients with diastrophic dysplasia both clinically and radiologically. Two legally aborted fetuses were dissected. The mean age of the patients was 16.2 years (newborn to 38) and the mean follow-up was 11.4 years (3 months to 34 years). The fetal hips and MRI of newborn infants showed congruity and no significant joint deformity. Flexion contracture of the hip became evident later in 93% and was progressive. The radiological appearance of the proximal femoral ossific nuclei was delayed and in 17% of males and 28% of females the ossific nuclei had not appeared by the age of 12 years. Radiological measurements differed considerably from reference values and were related to the rapid and progressive restriction of rotational movement and the increase in flexion contracture. The typical findings were flattening and inferomedial bulking of the femoral head and a double-hump deformation. The changes in the hip led to secondary osteoarthritis before early middle age. We describe the clinical and radiological measurements which define the early degeneration of the joint.

Abortion, Legal↗
PubMed1997

Craniofacial structure in diastrophic dysplasia--a cephalometric study.

Diastrophic dysplasia (DTD) is a well characterized, recessively inherited osteochondrodysplasia. Forty-eight patients with DTD were studied for craniofacial characteristics. Of these patients, 58% had cleft palate. A cephalometric analysis based on lateral cephalograms was performed. We observed a short anterior cranial base, vertical nasal bones, short and posteriorly positioned upper and lower jaws, increased anterior facial height, increase in the sagittal length of the body of the cervical vertebrae, and an abnormal dens of the second cervical vertebra. DTDST, in which mutations responsible for the disease occur, is a gene that codes for a sulphate transporter membrane protein. The craniofacial anomalies in DTD most likely result from deficient development and growth of cartilaginous structures and are probably due to defective sulfation of the proteoglycans of the cartilage.

Abnormalities, Multiple↗
PubMed1997

Growth in diastrophic dysplasia.

OBJECTIVE: To study the growth and its correlates in diastrophic dysplasia (DTD) and to construct standard growth curves for DTD. METHODS: Growth data of 121 Finnish patients with DTD were collected. Percentile growth curves for height and relative weight were constructed by using interpolated values from individual curves. Pubertal growth, intrafamilial variability, and correlates of adult height were assessed. RESULTS: The median adult height was 135.7 cm for the male and 129.0 cm for the female subjects. The growth failure was progressive partly because of absent or weak pubertal growth spurt. The severity of the growth failure varied greatly, even among siblings. The final height did not correlate with the midparental height but correlated well with the height at 1.0 and 5.0 years. The relative weight was normal in childhood but increased before puberty; 28% of the adults were overweight. Head circumference was normal. CONCLUSIONS: DTD interferes profoundly with normal growth and results in progressive growth failure of varying severity. The growth charts should prove useful in following up an individual patient with DTD; they may be used to predict adult height and to evaluate growth-promoting therapies.

Adolescent↗
PubMed1997

Abnormal ambulatory electrocardiographic findings in patients with the Marfan syndrome.

OBJECTIVES: The aim of this study was to assess the prevalence of cardiac dysrhythmias and abnormalities of conduction and repolarization in the Marfan-syndrome (MFS). SUBJECTS AND METHODS: Forty-five adult MFS patients (25 men) and healthy age and sex matched controls. A 24-h ambulatory electrocardiogram was recorded. RESULTS: There was no difference in heart rates between the two groups. Two MFS patients had atrial fibrillation. The median number of premature atrial beats was 12/24 h in the MFS group vs. 6/24 h in the controls (P < 0.05), and the respective medians of premature ventricular beats were 17/24 h vs. 1/24 h (P < 0.001). Five patients but no healthy person had salvos of > or = 3 premature ventricular complexes (P < 0.05). Ventricular premature beats with R on T configuration were recorded in nine patients but in none of the control subjects (P < 0.05). Both PQ and QT intervals at heart rates of 60, 80 and 100 beats min-1 were longer in the MFS group compared with healthy persons (P < 0.005). Also ST segment depression was seen more often in the MFS group (17/43 vs. 6/45; P < 0.05). In patients with MFS, the findings at ambulatory electrocardiography showed no association with echocardiographically determined aortic root diameter, left atrial diameter or left ventricular diameters, wall thickness and systolic function. Nor did the electrocardiographic findings correlate with the presence of mitral or tricuspid valve prolapse. CONCLUSIONS: Patients with MFS have a higher prevalence of cardiac dysrhythmias than healthy persons. Likewise they have prolonged atrio-ventricular conduction time and disturbed depolarization as suggested by longer QT intervals and more common ST segment depression.

Adult↗