amish lethal microcephaly amish lethal microcephaly amish lethal microcephaly is a rare genetic disorder which is characterized by severe microcephaly (small head) from birth, brain hypoplasia (underdeveloped brain), micrognathia (small chin), irritability (at second or third month of age), seizures, problems controlling their body temperature, high levels of alpha-ketogluraic acid in their urine, and less commonly hepatomegaly (large liver). babies with this condition typically die when they are 6 months old. this disorder was named after the amish since, in old order amish communities in pennsylvania, it affects 1 in 500 babies, while 1 in 11 people in the same communities are unaffected carriers of the (recessive) mutation that causes the disorder, it has not been found outside this population. amish lethal microcephalyother namesmicrocephaly, amish type amish letal microcephaly is inherited in an autosomal recessive fashion.specialtymedical geneticssymptomsliver, brain and craniofacial abnormalitiescomplicationsdeathusual onsetbirthdurationaffected baby's entire life-spancausesgenetic mutation and founder effectdifferential diagnosismicrocephaly, sudden infant death syndromepreventionnonefrequency1 in 500 babies inside old order amish communities in pennsylvania this disorder is caused by mutations in the slc25a19 gene in chromosome 17q25, it follows an autosomal recessive inheritance pattern