multiple congenital anomalies-hypotonia-seizures syndrome 3
Findings
No curated finding names multiple congenital anomalies-hypotonia-seizures syndrome 3 yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
A rare congenital disorder of glycosylation characterized by neonatal hypotonia, global development delay, developmental regress and severe to profound intellectual disability, infantile onset seizures that are initially associated with febrile episodes with subsequent transition to unprovoked seizures, impaired vision with esotropia and nystagmus, progressive cerebral and cerebellar atrophy, skeletal abnormalities (including brachycephaly, scoliosis, slender long bones, delayed bone age, pectus excavatum and osteopenia), inverted nipples and dysmorphic features including high and narrow forehead, frontal bossing, short nose, depressed nasal bridge, anteverted nares, high palate and wide open mouth consistent with facial hypotonia. Other features may include cardiac abnormalities (such as patent ductus arteriosus, atrial septal defects), urogenital abnormalities (such as nephrocalcinosis, urolithiasis), and low plasma concentration of alkaline phosphatase.
Definition from the Mondo Disease Ontology (MONDO:0014165), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal recessive inheritance
- Onset and course
- Congenital onset
HPO, annotations 2026-09-02
Features
77 features
What the disease is reported to present with, and how often among people who have it — never how often a feature means the disease. HPO, annotations 2026-09-02.
- Cerebral visual impairmentHPOHP:0100704
- 4 of 4 reported patients
- Very frequent (80% to 99% of cases)
- Delayed skeletal maturationHPOHP:0002750
- 4 of 4 reported patients
- Frequent (30% to 79% of cases)
- HypermetropiaHPOHP:0000540
- 4 of 4 reported patients
- Frequent (30% to 79% of cases)
- HypotoniaHPOHP:0001252
- 4 of 4 reported patients
- Very frequent (80% to 99% of cases)
- Intellectual disabilityHPOHP:0001249
- 4 of 4 reported patients
Genes
1 gene
Germline variants in the gene encoding each protein, as classified by GenCC submitters, each in their own words. Limited, disputed and refuted submissions are listed too.
- PIGTHGNC:14938
- Definitive · ClinGen · Autosomal recessive · 2025
- Definitive · G2P · Autosomal recessive · 2016
- Strong · Ambry Genetics · Autosomal recessive · 2024
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal recessive · 2022
- Strong · PanelApp Australia · Autosomal recessive · 2025
- Supportive · Orphanet · Autosomal recessive · 2021
Where it sits
Other names
7 names
Resolves to: multiple congenital anomalies-hypotonia-seizures syndrome 3
- Also called
- congenital disorder of glycosylation due to PIGT deficiencyLFSSMCAHS type 3multiple congenital anomalies-hypotonia-seizures syndrome type 3multiple congenital anomalies/dysmorphic syndrome-intellectual disability caused by mutation in PIGTPIGT multiple congenital anomalies/dysmorphic syndrome-intellectual disabilityPIGT-CDG