Ambiguous Genitalia Associated with an Extremely Rare Syndrome: A Case Report of XLAG Syndrome and Review of the Literature.

X-linked lissencephaly, absent corpus callosum, and epilepsy of neonatal onset with ambiguous genitalia comprises the XLAG syndrome and only 15 cases have been reported in literature. Due to its rarity, the exact clinical course and outcome are not known. Exact associations of this disease are also elusive. Hereby we are reporting this extremely rare entity and we searched the English literature extensively to get consolidated knowledge regarding this entity that would help the readers. Pre-natal radiological work-up can detect these malformations, which should be followed by medical termination, counseling and karyotyping. Till date the longest survival noted was 4 years only.

Early asymmetric inter-hemispheric transfer in the auditory network: insights from infants with corpus callosum agenesis.

The left hemisphere specialization for language is a well-established asymmetry in the human brain. Structural and functional asymmetries are observed as early as the prenatal period suggesting genetically determined differences between both hemispheres. The corpus callosum is a large tract connecting mostly homologous areas; some have proposed that it might participate in an enhancement of the left-hemispheric advantage to process speech. To investigate its role in early development, we compared 13 3-4-month-old infants with an agenesis of the corpus callosum ("AgCC") with 18 typical infants using high-density electroencephalography in an auditory task. We recorded event-related potentials for speech stimuli (syllables and babbling noise), presented binaurally (same syllable in both ears), monaurally (babbling noise in one ear) and dichotically (syllable in one ear and babbling noise in the other ear). In response to these stimuli, both groups developed an anterior positivity synchronous with a posterior negativity, yet the topography significantly differed between groups likely due to the atypical gyration of the medial surface in AgCC. In particular, the anterior positivity was lateral in AgCC infants while it covered the midline in typical infants. We then measured the latencies of the main auditory response (P2 at this age) for the different conditions on the symmetrical left and right clusters. The main difference between groups was a ~ 60 ms delay in typical infants relative to AgCC, for the ipsilateral response (i.e. left hemisphere) to babbling noise presented in the left ear, whereas no difference was observed in the case of right-ear stimulation. We suggest that our results highlight an asymmetrical callosal connectivity favoring the right-to-left hemisphere direction in typical infants. This asymmetry, similar to recent descriptions in adults, might contribute to an enhancement of left lateralization for language processing beyond the initial cortical left-hemisphere advantage.