brittle hair

Hypoparathyroidism, Familial Isolated

Clinical Characteristics
Ocular Features: 

Lens opacities may be present.

Systemic Features: 

The major signs and symptoms result from hypocalcemia. Neuromuscular irritability and various paresthesias may be present.  Some patients have  laryngeal spasm and latent tetany with grand mal seizures.  Alopecia, abnormal dentition and coarse brittle hair may be present.  Cognitive deficits and personality disorders are often a feature.  Brain imaging may show calcification of the basal ganglia.  Serum calcium levels are usually low while phosphorus levels are elevated.   Vitamin D precursor levels are usually low or low normal.

Genetics

Familial hypoparathyroidism may be due to mutations in the PTH gene (11p15.3) (either autosomal dominant or recessive inheritance) or in the GCMB gene (6p24.2) (autosomal dominant inheritance pattern).

There is also an X-linked form of hypoparathyroidism (307700) in which parathryroid tissue may be congenitally absent.

A family has been reported in which hypoparathryroidism was associated with lymphedema (247410) and progressive renal failure.  Ptosis, telecanthus, hypertrichosis, restrictive lung disease, and mitral valve prolapse may also be part of the disorder.

Pedigree: 
Autosomal dominant
Autosomal recessive
Treatment
Treatment Options: 

Normalization of calcium and phosphorus levels is a priority and this may result in some clearing of the lens opacities.  Cataract surgery may be indicated in selected individuals.

References
Article Title: 

Gurrieri Syndrome

Clinical Characteristics
Ocular Features: 

Tapetoretinal degeneration has been described in several patients.  Some patients have keratoconus with lens and corneal opacities.  Visual acuities have not been reported.  The full ocular phenotype must be considered unknown since most patients have not had full ophthalmic evaluations.

Systemic Features: 

Features of an osteodysplasia are among the most striking in this syndrome.  Short stature, brachydactyly, delayed bone age, osteoporosis, and hypoplasia of the acetabulae and iliac alae are usually present.  Birth weight is often low.  Joints may be hyperflexible as part of the generalized hypotonia. The eyes are deep-set, the nasal bridge is prominent, the midface is flat, and the supraorbital ridges are prominent giving the face a rather coarse look.  Prognathism with a prominent lower lip and dental malocclusion reinforce this appearance.  Seizures beginning in early childhood may be difficult to control.  Most patients have severe psychomotor retardation and never acquire speech.

Genetics

The genetics of this familial disorder remain unknown.  No locus or mutation has been identified but one patient had an absent maternal allele of the proximal 15q region as found in Angelman syndrome.

Orofaciodigital syndrome IX (258865) is another autosomal recessive syndrome sometimes called Gurrieri syndrome.  In Gurrieri’s original description of two brothers, chorioretinal lacunae, similar to those seen in Aicardi syndrome (304050), were present.  The systemic features are dissimilar, however.

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

No treatment is known.

References
Article Title: 
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