Abnormal spindle-like microcephaly gene detection in an autosomal recessive microcephalic Saudi patient with attention deficit hyperactivity disorder and mental retardation.

H autosomal recessive primary microcephaly (MCPH) is failure of normal fetal brain development, resulting in microcephaly (MIC) and mental retardation. It is caused by an abnormal spindlelike microcephaly (ASPM) gene mutation. It is a heterogeneous disorder, with at least 7 genetic loci. A mutation of the ASPM gene at the MPCH5 locus is the most common cause of MCPH. The ASPM associated protein is known as abnormal spindle protein or ASP Homolog. It is encoded by the ASPM gene, and is located on the long arm of chromosome 1, band 3, sub-band1 (1q31). The expressed protein product of the ASPM gene is essential for normal mitotic spindle function in embryonic neuroblasts. A 6-year-old Saudi girl presented to the outpatient department with epilepsy, cognitive decline, and hyperactivity. She had a history of 2 febrile seizures at age 9 months and 24 months consecutively followed by afebrile seizures at age 33 months. The seizures were mainly right sided clonic, with secondarily generalization, lasting more than one minute, with up rolling of eyes and oral cyanosis. They used to occur during sleep, and recurred up to 20 times per day. She was born second in order, from a consanguineous marriage after a full term pregnancy through a normal vaginal delivery. Birth weight was 2.75kg, with head circumference (HC) 30 cm, below the 3rd centile. The father’s HC is 59 cm, and mother’s HC is 55cm. Both at the 50th centiles. There is a strong family history of MIC in the younger brother and 2 paternal second cousins. The Apgar score at birth was within normal range, and neonatal history was uneventful. The child had normal gross motor development, but fine motor delay. Her speech was delayed; as she did not develop more than 2 words. Hearing and vision was intact. She was delayed socially with no symbolic play at 24 months. She was diagnosed with attention deficit hyperactivity disorder (ADHD) at the age of 4.5 years. On examination her HC was 43.1 cm at 33 months, below the 5th centile. Vital signs were stable. There were no neurocutaneous stigmata or dysmorphic features. Neurological examination showed intact cranial nerves, with equally reactive rounded pupils, normal fundi, with no restriction of eye movements, and symmetric face. Mouth opening and closure was normal. She had a normal response to sounds, turning her head to both sides without difficulty. The tongue was normal and in the midline. Bulk, tone, power, and reflexes were normal. The back was normal. All other systems were unremarkable. Renal, liver function, and electrolytes were normal. The serum amino acids and urinary organic acids were unremarkable. Her EEG was reported as left sided frontal spike and wave discharges. The brain MRI was unremarkable (Figure 1). On formal neurocognitive testing, her intelligence quotient was 62. Chromosomal karyotyping was unremarkable. A DNA genetic study was sent to assess the microcephalic gene, and the ASPM gene was detected. The cytosine nucleotide was replaced by a thymine nucleotide at position 8017 in a homozygous state (the resultant amino acid changed from glutamine to STOP