The question of genetic heterogeneity in tuberous sclerosis (TSC) was addressed by genetic linkage studies in eight affected families using nine polymorphic markers (EFD126.3, MCT136, ABO, ABL, AK1, and MCOA12 from distal 9q, and PBGD, MCT128.1, and 1CJ52.208M from distal 11q).
Two-point linkage analysis and multilocus linkage analysis were used to evaluate linkage between tuberous sclerosis and the markers ABO, MCT136, and AblK2.
The question of genetic heterogeneity in tuberous sclerosis (TSC) was addressed by genetic linkage studies in eight affected families using nine polymorphic markers (EFD126.3, MCT136, ABO, ABL, AK1, and MCOA12 from distal 9q, and PBGD, MCT128.1, and 1CJ52.208M from distal 11q).
Analysis of the basic genetic defect in tuberous sclerosis would be greatly expedited by definitive determination of the chromosomal location of the TSC gene or genes.
Analysis of the basic genetic defect in tuberous sclerosis would be greatly expedited by definitive determination of the chromosomal location of the TSC gene or genes.
Analysis of the basic genetic defect in tuberous sclerosis would be greatly expedited by definitive determination of the chromosomal location of the TSC gene or genes.
The regions that have been found to be linked to TSC in different families map to the positions of three enzymes, phenylalanine hydroxylase (12q22-24), tyrosinase (11q14-22), and dopamine-beta-hydroxylase (9q34), all of which are involved in the conversion of phenylalanine to catecholamine neurotransmitters or melanin.
The regions that have been found to be linked to TSC in different families map to the positions of three enzymes, phenylalanine hydroxylase (12q22-24), tyrosinase (11q14-22), and dopamine-beta-hydroxylase (9q34), all of which are involved in the conversion of phenylalanine to catecholamine neurotransmitters or melanin.
The regions that have been found to be linked to TSC in different families map to the positions of three enzymes, phenylalanine hydroxylase (12q22-24), tyrosinase (11q14-22), and dopamine-beta-hydroxylase (9q34), all of which are involved in the conversion of phenylalanine to catecholamine neurotransmitters or melanin.
We have previously demonstrated allele loss in hamartomas from patients with tuberous sclerosis for markers spanning the tuberous sclerosis gene on chromosome 16q13.3 (TSC2).
Major genes which cause tuberous sclerosis (TSC) and autosomal dominant polycystic kidney disease (ADPKD), known as TSC2 and PKD1 respectively, lie immediately adjacent to each other on chromosome 16p.
This finding, coupled with the mild physical expression of TSC in some family members, supports a hypothesis that the TSC2 gene may present phenotypically as mild skin signs and significant behavioural problems.
Analysis of TSC-associated hamartomas has shown loss of heterozygosity for the regions of chromosomes 9 and 16 known to harbour TSC genes, consistent with the occurrence of somatic 'second-hit' mutations.
Analysis of TSC-associated hamartomas has shown loss of heterozygosity for the regions of chromosomes 9 and 16 known to harbour TSC genes, consistent with the occurrence of somatic 'second-hit' mutations.