Lab Med Online.  2021 Apr;11(2):135-138. 10.47429/lmo.2021.11.2.135.

Neurofibromatosis Type I: Case Reports of Two Novel Mutations

• Lee HJ
• Kim UJ
• Kim WS
• Ko YJ
• Park G
• Jang SJ
• Kang SH

• KMID: 2525802
• DOI: http://doi.org/10.47429/lmo.2021.11.2.135

Abstract

Neurofibromatosis type 1 (NF1) is characterized by multiple café-au-lait spots, axillary and inguinal freckling, Lisch nodules in the iris, and fibromatous tumors of the skin. We performed direct sequencing of 58 exons comprising the NF1 gene along with the associated intronic regions in suspected cases of NF1. We have detected two different novel frameshift mutations in two cases, respectively. The first case involved a 59-year-old male presenting with neurofibromas and a positive family history of NF1. The patient presented with leiomyomas of the iliac bone and right adrenal gland, and an astrocytoma of the left cerebellum. The mutation in this patient was caused by heterozygous deletion of base A at nucleotide position 3108 (c.3108delA; p.Lys1036Asnfs*14). The second case involved a 25-month-old girl presenting with multiple café-au-lait spots and a positive family history of NF1. The mutation in this patient was caused by heterozygous deletion of base G at nucleotide position 7623 (c.7623delG;p.Ile2541Serfs*7). These novel mutations may be useful for advanced genetic counseling and clinical management of patients with NF1 and their families.

Keyword

Neurofibromatosis type I; NF1 gene; Frameshift mutation

Figure

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  Fig. 1 Tumors observed in Patient 1. (A) Leiomyoma in the right iliac bone. (B) Leiomyoma in the right adrenal gland. (C) Pilocytic astrocy­toma in the left cerebellum.

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  Fig. 2 Partial sequences of NF1 showing the mutations detected in this study. (A) Patient 1, c.3108delA (p.Lys1036Asnfs*14). (B) Patient 2, c.7623delG (p.Ile2541Serfs*7). Both mutations were heterozygous. Blue arrows indicate the locations of the variants.

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