Below are a collection of excerpts from biomedical research articles. Excerpts are separated by newlines. Your task is to answer a question based these excerpts. Your response should be formatted as a `json` array.

For instance, given excerpts from articles studying breast cancer, and the question "what are some common genes associated with breast cancer?", an answer might be formatted like: ["BRCA1", "BRCA2", "TP53", ...]. Only include answers that are mentioned in the provided exerpts. The array should always have at least one answer; do not respond with an empty array []. Do not include any text in your response other than the answer array.

Context: We detected a nonsense mutation in the gene encoding the transcription factor GFI1B (growth factor independent 1B) that causes autosomal dominant gray platelet syndrome.
The genetic defect responsible for gray platelet syndrome was recently identified in biallelic mutations in the NBEAL2 gene.
Here we show that mutations in NBEAL2 (neurobeachin-like 2), which encodes a BEACH/ARM/WD40 domain protein, cause GPS and that megakaryocytes and platelets from individuals with GPS express a unique combination of NBEAL2 transcripts.
Linkage analysis revealed a 63 cM region on the X chromosome between markers G10578 and DXS6797, which segregated with the platelet phenotype and included the GATA1 gene. Sequencing of GATA1 revealed a G-to-A mutation at position 759 corresponding to amino acid change Arg216Gln.
We identified a family with gray platelet syndrome (GPS) segregating as a sex-linked trait.
X-linked gray platelet syndrome due to a GATA1 Arg216Gln mutation

Question:
Which genes have been found mutated in Gray platelet syndrome patients?
["neurobeachin-like 2", "GATA1", "GFI1B"]