Identification of a novel KIF11 variant p.(Leu804Thrfs Ter13) in a case with isolated microcephaly

Microcephaly is a rare neurological condition, and it is characterized by a smaller head than other children of the same age and sex. Microcephaly with or without chorioretinopathy, lymphedema, or mental retardation (MLCRD) is a syndrome with a varying spectrum that occurs as a result of variants of KIF11 gene. A 3-year-old girl was presented to our clinic with microcephaly; she had no motor or growth retardation except microcephaly. After obtaining a normal karyotype and microarray result, Trusight One-Expanded Panel analysis showed NM_004523.4 (KIF11): c. 2409dupA (p. Leu804Thrfs Ter13) heterozygous pathogenic novel variant. Patients who have KIF11 mutation often also have different clinical features; in our case, the motor development is consistent with its peers and has a history of prenatal and postnatal microcephaly. Microcephaly can be caused by a variety of genetic mutations. In our case, firstly we identify the association of a novel de novo KIF11 gene duplication variant related to isolated microcephaly.