Table 1

Details of the studied patients and results after SacII cleavage

PatientDisease status and origin of mutationAge at samplingExpansion size (repeats)Description of the expansionAlleles after SacII digestionDescription of the alleles after SacII digestion
1DM, paternal33900–2800Numerous discrete bands900–2800Numerous discrete bands: full methylation
2Unknown30400–1200SmearFully cleavedFully unmethylated
3DM, paternal33200–400Two groups of very close bandsFully cleavedFully unmethylated
4CMD, probably maternal3 months1400One band1400One band: full methylation
5DM, paternal41300–900Two groups of very close bands300–900Two groups of very close bands: full methylation
6CMD, maternalNewborn700–1300Smear with predominant band at 1300700–1300Smear with predominant band at 1300: full methylation
7Unknown4700–1300Smear with predominant band at 1300700–1300Smear with predominant band at 1300: full methylation
8DM, maternal20700–1600Smear with predominant allele at 1600860One band: partial methylation
9UnknownUnknown200–500SmearFully cleavedFully unmethylated
10DM, paternal33700–1600Smear with predominant allele at 1600700–1160Bands of 700, 990, 840 and 1160: partial methylation
11DM, maternal30600–1200Smear680–1170Bands of 680 and 1170: partial methylation
12DM, paternal24200–480SmearFully cleavedFully unmethylated
13DM, probably maternal33200–480SmearFully cleavedFully unmethylated
14DM, maternal27680–900Smear680–860Bands of 680 and 860: partial methylation
15DM, paternal45500–1300Smear840–990Bands of 840 and 990: partial methylation
16DM, paternal38500–1300SmearFully cleavedFully unmethylated
17Unknown43500–1650Smear1300One band: partial methylation
18Unknown30220–370SmearFully cleavedFully unmethylated
19DM, maternal29250–1400Smear850–1000Bands of 850 and 1000: partial methylation
20DMUnknown180–2200Smear400–1700Discrete bands of 400, 900 and 1700: partial methylation
21UnknownUnknown300–2600Smear600–2600Discrete bands of 600, 950, 1200, 1500, 1600 and 2600: partial methylation
22Infantile form, maternal inheritance141000–2600Smear1300One band: partial methylation
  • Full methylation indicates that all alleles appeared to carry a methylated SacII site.

  • CMD, disease onset is congenital; DM, disease onset is not congenital.