Focal dermal hypoplasia is a form of ectodermal dysplasia. It is a multisystem disorder characterized primarily by skin manifestations to the atrophic and hypoplastic areas of skin which are present at birth. These defects manifest as yellow-pink bumps on the skin and pigmentation changes. The disorder is also associated with shortness of stature and some evidence suggests that it can cause epilepsy. Genetics
Focal dermal hypoplasia has been associated with PORCN gene mutations on the X chromosome. 90% of the individuals who are affected with the syndrome are female: the commonly accepted, though unconfirmed, explanation for this is that the non-mosaic hemizygous males are not viable.The differential diagnosis of focal dermal hypoplasia (Goltz) syndrome includes autosomal recessive Setleis syndrome due to TWIST2 gene mutations. It associated with morning glory anomaly, polymicrogyria, incontinentia pigmenti, oculocerebrocutaneous syndrome, Rothmund-Thomson syndrome and microphthalmia with linear skin defects (also known as MLS) syndrome because they are all caused by deletions or point mutations in the HCCS gene. Diagnosis
Goltz Syndrome is a very rare diagnosis. To date, there are under 25 cases of Goltz Syndrome in the United States. Treatment
Management is targeted toward the various soft tissue and skeletal anomalies, with the goal of achieving optimal functional and cosmetic results. Eponyms
Jessner-Cole syndrome
The disorder was first formally recognized by dermatologists, Max Jessner and Harold Newton Cole, in the early 20th century. Jessner and Coles papers were referenced more than any others in the first half of the 20th century.
There is currently no international consensus on the definition of mild HPA, however, it is most frequently diagnosed at blood Phe levels between 2–6 mg/dL.Phenylalanine is a large, neutral amino acid (LNAA). LNAAs compete for transport across the blood–brain barrier (BBB) via the large neutral amino acid transporter (LNAAT). If phenylalanine is in excess in the blood, it will saturate the transporter. Excessive levels of phenylalanine tend to decrease the levels of other LNAAs in the brain. As these amino acids are necessary for protein and neurotransmitter synthesis, Phe buildup hinders the development of the brain, causing intellectual disability.Recent research suggests that neurocognitive, psychosocial, quality of life, growth, nutrition, bone pathology are slightly suboptimal even for patients who are treated and maintain their Phe levels in the target range, if their diet is not supplemented with other amino acids.Classic PKU affects myelination and white matter tracts in untreated infants; this may be one major cause of neurological problems associated with phenylketonuria. Differences in white matter development are observable with magnetic resonance imaging. Abnormalities in gray matter can also be detected, particularly in the motor and pre-motor cortex, thalamus and the hippocampus.It was recently suggested that PKU may resemble amyloid diseases, such as Alzheimers disease and Parkinsons disease, due to the formation of toxic amyloid-like assemblies of phenylalanine. Tetrahydrobiopterin-deficient hyperphenylalaninemia
A rarer form of hyperphenylalaninemia is tetrahydrobiopterin deficiency, which occurs when the PAH enzyme is normal, and a defect is found in the biosynthesis or recycling of the cofactor tetrahydrobiopterin (BH4).