Linkage analysis of six Chinese families with neurofibromatosis type 1 (NF1) confirms the location of the NF1 gene to the region of the proximal long arm of chromosome 17, as in Caucasian populations.
We report the detailed clinical presentation and molecular features of a spinal neurofibromatosis familial case where a 40-year-old woman, presenting with multiple bilateral spinal neurofibromas and no other clinical feature of neurofibromatosis type 1 (NF1), inherited a paternal large multiexonic deletion (c.5944-?_7126+?del) which resulted in NF1 gene haploinsufficiency at the RNA level.
We conducted a mutation analysis of the most conserved region of the neurofibromatosis type 1 (NF1) gene, the guanine triphosphatase (GTPase) activating protein (GAP)-related domain (NF1 GRD), to which the function of tumour suppressor is attributed.
The probability of finding three non-identical NF1 gene lesions arising de novo in a family with NF1 is very remote, too low to be readily accepted as mere coincidence.
Thorough investigation of the somatic mutation spectrum has thus far been hampered by the large size of the NF1 gene and the considerable proportion of NF1 heterozygous cells within the tumors.
To better localize the end points of these translocation events, and the NF1 gene (NF1) itself, human cosmids were isolated and mapped in the immediate vicinity of NF1.
The duplication involves the neurofibromatosis type I (NF1) gene and overlaps with long-range unusual deletions of the NF1 region, extending over 17q12 region and associated with renal cysts and diabetes (RCDA).
Although the search for mutations in the gene has proved difficult, germline mutation analysis has shown that around 82% of all the fully characterised NF1 specific mutations so far predict severe truncation of neurofibromin.
Because this mutation has been described in multiple Caucasian and Japanese families, the codon CGA for Arg-1947 in the NF1 gene is considered to be a hotspot for mutation in neurofibromatosis type 1 in all ethnic groups.