There is a 25% chance that both parents will pass the gene to their child, resulting in hydranencephaly. Genetic hydranencephaly afflicts both males and females in equal numbers. Post-natal brain injury
Though hydranencephaly is typically a congenital disorder, it can occur as a postnatal diagnosis in the aftermath of meningitis, intracerebral infarction, ischemia, or a traumatic brain injury. Diagnosis
An accurate, confirmed diagnosis is generally impossible until after birth, though prenatal diagnosis using fetal ultrasonography (ultrasound) can identify characteristic physical abnormalities. After birth, diagnosis may be delayed for several months because the infants early behavior appears to be relatively normal. The most accurate diagnostic techniques are thorough clinical evaluation (considering physical findings and a detailed patient history); advanced imaging techniques, such as angiography, computerized tomography (CT scan), and magnetic resonance imaging (MRI); and (more rarely) transillumination. However, diagnostic literature fails to provide a clear distinction between severe obstructive hydrocephalus and hydranencephaly, leaving some children with an unsettled diagnosis.Preliminary diagnosis may be made in utero via standard ultrasound, and can be confirmed with a standard anatomy ultrasound. Hydranencephaly is sometimes misdiagnosed as bilaterally symmetric schizencephaly (a less destructive developmental process on the brain), severe hydrocephalus (cerebrospinal fluid excess within the skull), or alobar holoprosencephaly (a neurological developmental anomaly). Once destruction of the brain is complete, the cerebellum, midbrain, thalami, basal ganglia, choroid plexus, and portions of the occipital lobes typically remain preserved to varying degrees.
Other types of genetic cystic kidney disease include juvenile nephronophthisis (JNPHP), medullary cystic kidney disease (MCKD), and glomerulocystic kidney disease (GCKD). Polycystic Kidney Disease
PKD causes numerous cysts to grow in the kidneys. These cysts are filled with fluid and if they grow excessively, changing the shape of them and making them larger, leading to kidney damage. Mutations in genes PKD1 and PKD2 are responsible for autosomal dominant polycystic kidney disease (ADPKD), which is typically diagnosed in adulthood. Those genes encode for polycystic proteins and mutations regarding those genes are inherited and responsible for the disorder of autosomal dominant cystic kidney disease. In the United States, more than half a million people have PKD, making it the fourth leading cause of kidney failure. PKD affects all races and genders equally and those with PKD have a possibility of developing cysts in other organs such as liver, pancreas, spleen, ovaries, and large bowel. Usually, these latter cysts do not impose a problem. Half of patients have no manifestation of symptoms, but symptoms may include: hematuria, back or abdominal pain, or the development of hypertension. The disease is usually manifested before age 30, and 45% develop kidney failure by age 60. Mutation in the HDK1 gene is currently thought to be responsible for autosomal recessive polycystic kidney disease (ARPKD), which can be diagnosed in the womb, shortly after birth, and usually before 15 years of age. Cause
The site of preference for cyst development is the renal tubule.