{
  "abstract": "A woman in her mid-30s at 21 weeks’ gestation was referred to the maternal fetal medicine clinic following the detection of fetal megacisterna magna with midline shift on routine ultrasound. Detailed neurosonography subsequently demonstrated hemimegalencephaly, persistent megacisterna magna (measuring 10.5 mm) and progressive midline shift ( figure 1). Additional intracranial abnormalities included dilated third and fourth ventricles, absence of the cavum septi pellucidi and agenesis of the corpus callosum (CC) (figures 2–6). Amniocentesis was performed without complication. Whole-exome sequencing identified a pathogenic variant, NM_005465.7:c.49G>A (p.Glu17Lys), located in exon 3 of the AKT3 gene (chr1: 243695714C>T, hg 38), with a 21% mutation burden. Variants in AKT3 are associated with Megalencephaly-Polymicrogyria-Polydactyly-Hydrocephalus syndrome 2 and belong to disorders involving dysregulation of the PI3K-AKT-mTOR pathway, which regulates cell growth and proliferation. Fetal brain MRI was not performed as the service is not available in our institution or nearest referral centre within the state. The challenges of in utero MRI remain twofold: in terms of availability of imaging and expertise in interpretation. Clinical assessment and management were therefore based on detailed ultrasonographic evaluation. Following multidisciplinary counselling regarding the poor neurological prognosis, the patient opted for termination of pregnancy at 25 weeks’ gestation. Postnatal cranial ultrasound confirmed a severe malformation of cortical development characterised by bilateral lissencephaly, hemimegalencephaly, agenesis of CC and cerebellar hypoplasia(figures 7 and 8). Parental segregation analysis did not detect the variant in either maternal or paternal samples, confirming a de novo mutation.",
  "authors": [
    {
      "affiliations": [
        "OBGYN, Sibu Hospital, Sibu, Sarawak, Malaysia",
        "Medical Faculty, SEGi University College Faculty of Medicine, Sibu, Sarawak, Malaysia"
      ],
      "name": "Leh Ping Sii"
    },
    {
      "affiliations": [
        "OBGYN, Sarawak General Hospital, Kuching, Sarawak, Malaysia"
      ],
      "name": "Hian Yan Voon"
    },
    {
      "affiliations": [
        "OBGYN, Sibu Hospital, Sibu, Sarawak, Malaysia"
      ],
      "name": "Ing Hie Wong"
    }
  ],
  "title": "Severe fetal brain malformation: prenatal ultrasound spectrum",
  "uid": "ddda578a-4200-5ee7-ba2f-3c3f4d0773b3"
}