Galloway-Mowat syndrome (GMS), also known as Microcephaly-Hiatal Hernia-Nephrotic syndrome, is an extremely rare genetic disorder that is characterized by the association of nephrotic syndrome and central nervous system anomalies. Approximately 40 cases have been reported to date with Galloway-Mowat syndrome. Physical features may include microcephaly, craniofacial abnormalities, focal glomerulosclerosis and/or diffuse mesangial sclerosis, resulting in nephrotic syndrome; and in many cases, esophageal hiatus in the diaphragm; hiatal hernia. The nephrotic syndrome is mostly resistant to any form of treatment and progresses to end-stage renal failure. Neurological symptoms include microcephaly, psychomotor retardation, convulsions, hypotonia, abnormal cerebral giri and sulci, cortical atrophy, hydrocephalus due to aqueductal stenosis, porencephaly or encephalomalacia. Mental retardation may also be present. Galloway syndrome is inherited as an autosomal recessive trait thought to be caused by mutations in the WD Repeat-Containing Protein 73 (WDR73) gene.
Hazza and Najada (1999) described a 12 year-old boy with Galloway-Mowat syndrome born to first cousin consanguineous parents. He presented with microcephaly, mental retardation, and had severe delay in developmental skills. He was diagnosed with the nephrotic syndrome at the age of seven years. He had subnormal mentality, with head circumference below the 3rd percentile. He had an abnormally shaped skull, narrow forehead, large and low set ears, micrognathia with malocclusion and a moon shaped face; all typical dysmorphic features of Galloway-Mowat syndrome. The late age of onset of nephrotic syndrome in this case prompted Hazza and Najada (1999) to suggest that the condition could represent a new variant of Galloway Mowat syndrome.
Megarbane et al, 2001 described a large inbred Druze Lebanese family, in which five children presented with severe mental retardation, short stature, speech defect, cerebellar ataxia, microcephaly, optic atrophy, abnormal osmiophilic pattern of skin vessels, and cerebellar atrophy; Delague et al, 2002 undertook a genome wide screening using homozygosity mapping upon 15 members of the family diagnosed by Megarbane et al.