[A genetic case study of neurofibromatosis type 1-microdeletion syndrome caused by atypical 17q11.2 microdeletion].

OBJECTIVE

To provide appropriate treatment strategy and precise genetic counseling through studying the phenotype and genotype of a patient featuring learning difficulty and abnormal gait.

METHODS

Detailed history taking, physical examination and auxiliary examination (including neuropsychological evaluation, brain imaging and skeletal system X ray) were conducted. The patient was also analyzed by whole exome sequencing, G banding karyotyping and array-based comparative genomic hybridization (aCGH). Multiples ligation-dependent probe amplification (MLPA) was applied to his parents to determine the origin of genomic variation.

RESULTS

In addition to obvious dermatological manifestation (Cafe-au-Lait spots), the patient also had facial abnormalities, ocular disorders, skeletal malformations, neurological manifestations, psychiatric and behavioral abnormalities. Whole exome sequencing and G banding karyotyping were both negative. aCGH has identified a microdeletion at 17q11.2, which encompassed the NF1 and neighboring genes. Neither parents has carried the same microdeletion by MLPA analysis.

CONCLUSION

The patient had a de novo 17q11.2 microdeletion, which probably accounted for his neurofibromatosis type 1-microdeletion syndrome phenotype.