What is Acromelic Frontonasal Dysostosis?
Acromelic Frontonasal Dysostosis is a rare disease and a rare subtype of frontal dysostosis syndrome, which also presents with limb abnormalities and central nervous system malformations in affected individuals.
It occurs in less than 1 in 1 million live births.
Abnormalities affecting the digits and unique facial features are common with the syndrome.
This syndrome is also known as:
Acromelic frontonasal “dysplasia”
What gene change causes Acromelic Frontonasal Dysostosis?
Mutations in the ZSWIM6 gene are responsible for this syndrome, which is believed to be inherited in an autosomal dominant pattern.
In the case of autosomal dominant inheritance just one parent is the carrier of the gene mutation, and they have a 50% chance of passing it onto each of their children. Syndromes inherited in an autosomal dominant inheritance are caused by just one copy of the gene mutation.
What are the main symptoms of Acromelic Frontonasal Dysostosis?
Preaxial polydactyly, or extra digits on the foot closest to the big toes is one major defining feature of the syndrome. As are abnormal toenails.
Facial characteristics of the syndrome include an abnormal area between the eyebrows, clefting of the nose and nasal tip, a broader than average nasal tip, wide-set eyes, a large fontanelle, a short and broad skull, club feet and a cleft palate.
Possible clinical traits/features:
Intellectual disability, Meningocele, Midline defect of the nose, Myopia, Cleft upper lip, Cryptorchidism, Large sella turcica, Encephalocele, Ventriculomegaly, Agenesis of corpus callosum, Hypoplasia of the corpus callosum, Hypertelorism, Glaucoma, U-Shaped upper lip vermilion, Vertical clivus, Bifid nose, Preaxial polydactyly, Retrocerebellar cyst, Telecanthus, Ptosis, Hypopituitarism, Talipes equinovarus, Onychogryposis, Autosomal dominant inheritance, Seizure, Syndactyly, Choroid plexus cyst, Cleft palate, Brachycephaly, Abnormality of the nasal alae, Broad nasal tip.
How is it diagnosed?
To find out if someone has a diagnosis of Acromelic Frontonasal Dysostosis, it is important to have a consultation and evaluation with a clinical genetic specialist. Specialists may also suggest specific genetic testing or other types of tests to help reach a diagnosis. FDNA’s AI technology can help speed up the diagnostic process by analyzing facial features and other health information.
