Table 1 NF1 gene mutations identified in neurofibromatosis type 1 (NF1) patients with somatic mosaicism
Manifestation of the mosaic phenotypeNo. of patients (designation)NF1 gene mutation identifiedBreakpoint localisationPercentage of cells bearing the mutation inRef
Peripheral bloodUnaffected skin fibroblastsHyper-pigmented skin fibroblastsCALM melano-cytesCALM fibro-blastsNeurofibroma Schwann cellsNeurofibroma fibroblastsBuccal smearHair
Segmental1Large NF1 deletion of atypical sizeUnknownNDND17–24%ND33
Segmental1 (SNF1–3)Atypical NF1 deletion of 1.84–2.8 Mb*NF1–REPc4%<7%ND<7%NDNDNDND23
Segmental1 (SNF1–2)Atypical NF1 deletion of >1.3 MbNF1-REPa, SUZ122%<7%<7%ND<7%NDND23
Segmental1 (SNF1–1)†R681X4%7–8%NDND2%23
41–48%9%
47–56%19–26%
Segmental1‡R1947XND‡ND‡68
Generalised1 (U161)Large NF1 deletion of unknown sizeUnknownHigh, not quantifiedND117
Generalised1 (U113)Large NF1 deletion of unknown sizeUnknown+, not quantified118
Generalised1 (867)Large NF1 deletion of unknown sizeUnknown+, not quantified119
Generalised1 (5b)Large NF1 deletion of unknown sizeUnknown83%ND120
Generalised1 (95–870P)Large NF1 deletion of unknown sizeUnknown77–84%0%121
Generalised1100 kb deletion involving exons 13–28Intragenic20.5%0.9%2.4%122
Generalised1 (NR)Large NF1 deletion of unknown sizeUnknown+, not quantified123
Generalised1Atypical NF1 deletion of >1.7 MbUnknown33%58%124
Generalised1 (811-M)Type 2 deletionSUZ12/SUZ12P93%59
Generalised1 (KCD-3)Type 2 deletionSUZ12/SUZ12P92%51%59
Generalised1 (697)Type 2 deletionSUZ12/SUZ12P97%59%59
Generalised1 (736)Type 2 deletionSUZ12/SUZ12P94%59%59
Generalised1 (1630)Type 2 deletionSUZ12/SUZ12P92%59
Generalised1 (IL-39)Type 2 deletionSUZ12/SUZ12P70%15%59
Generalised1 (1104)Type 2 deletionSUZ12/SUZ12P84%8%59
Generalised1 (WB)Type 2 deletionSUZ12/SUZ12P94%59
Generalised1 (938)Type 2 deletionSUZ12/SUZ12P91%80%59
Generalised1 (1502)Type 2 deletionSUZ12/SUZ12P97%70%59
Generalised1 (488)Type 2 deletionSUZ12/SUZ12P98%56%59
Generalised1 (928)Type 2 deletionSUZ12/SUZ12P100%80%55%59
Generalised1 (HC)§Type 2 deletionSUZ12/SUZ12P100%59
  • CALM, café-au-lait macules.

  • –, not investigated; ND, mutation not detectable; +, deletion detected.

  • *In addition to the microdeletion, a c.2325+1G→A mutation was identified in neurofibroma derived Schwann cells in melanocytes from different CALM.

  • †Patient had segmental NF1 with neurofibromas on their own. Schwann cells for analysis were isolated from three different neurofibromas.

  • ‡The R1947X mutation was identified in the affected daughter, in 29/146 clones from maternal keratinocytes cultured from the affected region, and in 12/136 clones from maternal fibroblasts.

  • §Somatic mosaicism identified by the analysis of polymorphic markers using DNA isolated from buccal smears.