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It is an extremely rare inherited disorder characterized by metallic silvery hair color, moderate pigment abnormalities of the skin, and early-onset profound primary central nervous system dysfunctions. Elejalde Syndrome manifests during infancy. The onset of the neurologic signs has been reported between 1 month and 11 years of age. The neurological features include severe developmental delay, seizure activity, exotropia, nystagmus, and ataxia. In comparison with the Griscelli Syndrome Type II and Chediak-Higashi Syndrome, individual affected with Elejalde Syndrome do not present immune system dysfunctions (see below).
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Melanolysosomal Neurocutaneous Syndrome; Griscelli Syndrome Type 1. (Caveat: The name Elejalde Syndrome has also been used synonymously for Acrocephalopolysyndactylous Dysplasia. To avoid confusion, we recommend reserving this name for the syndrome described here.)
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Elejalde Syndrome (ES) was first described in 1977 by B. R. Elejalde in three consanguineous families in Columbia.
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It is an extremely rare medical condition with a limited number of individuals reported in the literature to date. The largest series of patients has been reported in Mexico. In the United States, 20 patients have been diagnosed with this medical condition until 2017. There is no known racial or geographical predilection. It seems to affect male and female equally.
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Autosomal recessive. It has been suggested that Elejalde Syndrome is the same disease entity as Griscelli Syndrome Type I that is caused by mutations in the MYO5A gene. Candidate genes for Elejalde Syndrome have been sought in a variety of genes involved in organellogenesis and intracellular trafficking. These genes are directly or indirectly involved in pigmentation disorders throughout the expression of adaptor-like protein complex (AP)-3 factor, which is involved in the budding of coated vesicles from the Golgi system.
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Abnormal melanocytes, melanosomes, and inclusion bodies in fibroblasts may be present. There are speculations that myosin V protein may be affected and probably responsible for the severe generalized hypotonia. The molecular basis of the disease remains to be elucidated.
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Light microscopy of the hair is characterized by the presence of small and large melanin clumps irregularly distributed along the hair shaft but predominantly in the medulla. Skin biopsy specimens may reveal a normal number of melanocytes but irregular distribution and irregular size of melanin granules in the basal layer. Electron microscopy of the skin reveals melanocytes with melanosomes of various sizes and at various developmental stages. Because of a maturation defect, melanization of the melanosomes is incomplete; however, in contrast to ☞Griscelli Syndrome Type II and ☞Chediak-Higashi Syndrome (the two other “Silvery Hair Syndromes”), both humoral and cellular immunity are normal.
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Scalp hair, eyelashes, and eyebrows are ...