Birk-Landau-Perez Syndrome
Patient Information
Characteristics
Background and History
This is a rare, inherited primarily neurological disorder so far reported only in 6 children of a consanguineous multigenerational Bedouin family.
Clinical Correlations
Children are born without external abnormalities following normal gestation. This is a disease of progressive neurological deterioration with the first signs becoming apparent by the age of two years. Speech is lost and abnormal movements become evident leading to balance problems and frequent falls. General muscle weakness is present. Cognitive impairment progresses and leads to profound intellectual disability. No brain abnormalities are present upon imaging.
The eyes do not fixate on targets but may follow targets with abnormal jerky movements. The lids often droop (ptosis). The eyes are often not lined up symmetrically.
Some individuals develop a kidney disease but none have been reported to have kidney failure. They may have hypertension and blood chemistry changes.
Genetics
Inheritance
This is an autosomal recessive disorder in which the clinically normal parents carry a single mutation and the affected children have two copies. Such parents transmit a 25% risk for this condition to each of their children.
Pedigree
Autosomal recessive
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.
Diagnosis and Prognosis
This disorder is not apparent at birth but the first signs appearing between 1 and 2 years of age likely requires the diagnostic collaboration of neurologists and ophthalmologists. No treatment is available for the general condition and nothing is known regarding longevity.
Physical therapy could be helpful in early stages and kidney function should be monitored with correction of anomalies as appropriate.
Printer Friendly Version: Ctrl/Cmd+P