Generalized hypotonia is evident but lower limb deep tendon reflexes may be present. Normal developmental milestones are never achieved and patients are unresponsive to their environment. [disorders.eyes.arizona.edu]

These molecules are present in cells and tissues throughout the body, and they are particularly abundant in the nervous system. [medlineplus.gov]

(DGS/VCFS) region (proximal, A-D) (includes TBX1) Loss ISCA-37446-Loss Region 2 reviews MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown Sources ClinGen Expert Review Green Phenotypes micrognathia neonatal hypocalcemia, which may present [panelapp.genomicsengland.co.uk]

• Poor Feeding

  Irritability, poor feeding, vomiting and failure to thrive are important features. Generalized hypotonia is evident but lower limb deep tendon reflexes may be present. [disorders.eyes.arizona.edu]

• Brittle Hair

  Hair Brain Syndrome Amish brittle hair syndrome Amish brittle hair syndrome Amish brittle hair syndrome Amish brittle hair syndrome Amish Christmas Amish Church Amish Church Amish Church Amish Church Amish clip Amish clip Amish clip Amish Country Byway [medical-dictionary.thefreedictionary.com]

• Irritability

  Irritability, poor feeding, vomiting and failure to thrive are important features. Generalized hypotonia is evident but lower limb deep tendon reflexes may be present. [disorders.eyes.arizona.edu]

  Within the first few weeks after birth, affected infants become irritable and develop feeding difficulties and vomiting that prevent them from growing and gaining weight at the usual rate. [medlineplus.gov]

• Global Developmental Delay

  developmental delay Generalized hypotonia, Global developmental delay, Intellectual disability, Autistic behavior, Stereotypic behavior, Seizures, Abnormality of movement, Cortical visual impairment Autistic behavior Tags Green Green List (high evidence [panelapp.genomicsengland.co.uk]

Treatment Treatment Options: There is no known treatment for the enzyme deficiency. Seizures respond poorly to anti-epileptic medications. [disorders.eyes.arizona.edu]

The seizures associated with GM3 synthase deficiency tend to be resistant (refractory) to treatment with antiseizure medications. GM3 synthase deficiency profoundly disrupts brain development. [medlineplus.gov]

[…] monoallelic and biallelic (but BIALLELIC mutations cause a more SEVERE disease form), autosomal or pseudoautosomal Sources Expert Review Phenotypes Developmental epileptic encephalopathy intractable seizures global developmental delay and cognitive delay treatment [panelapp.genomicsengland.co.uk]

Etiology of vision loss in ganglioside GM3 synthase deficiency. Ophthalmic Genet. 2006 Sep;27(3):89-91. [medlineplus.gov]

Within the first few weeks after birth, affected infants become irritable and develop feeding difficulties and vomiting that prevent them from growing and gaining weight at the usual rate. [medlineplus.gov]