Phenotypes associated with the disease GM1 gangliosidosis type 2 (OMIM:230600):
- Generalized myoclonic seizure (HP:0002123): A generalized myoclonic seizure is a type of generalized motor seizure characterized by bilateral, sudden, brief (<100 ms) involuntary single or multiple contraction of muscles or muscle groups of variable topography (axial, proximal limb, distal). Myoclonus is less regularly repetitive and less sustained than is clonus. Evidence: IEA. (OMIM:230600)
- Protruding tongue (HP:0010808): Tongue extending beyond the alveolar ridges or teeth at rest. Evidence: PCS. Frequency: 1/1. (PMID:30187681)
- Narrow mouth (HP:0000160): Distance between the commissures of the mouth more than 2 SD below the mean. Alternatively, an apparently decreased width of the oral aperture (subjective). Evidence: PCS. Frequency: 1/1. (PMID:30187681)
- Hepatomegaly (HP:0002240): Abnormally increased size of the liver. Evidence: PCS. Frequency: 1/1. (PMID:30187681)
- Ataxia (HP:0001251): Ataxia refers to impaired coordination of voluntary muscle movement. Cerebellar ataxia refers to ataxia due to dysfunction of the cerebellum. This causes a variety of elementary neurological deficits including asynergy (lack of coordination between muscles, limbs and joints), dysmetria (lack of ability to judge distances that can lead to under- or overshoot in grasping movements), and dysdiadochokinesia (inability to perform rapid movements requiring antagonizing muscle groups to be switched on and off repeatedly). Evidence: IEA. (OMIM:230600)
- Generalized hypotonia (HP:0001290): Generalized muscular hypotonia (abnormally low muscle tone). Evidence: PCS. Frequency: 1/1. (PMID:30187681)
- Coarse facial features (HP:0000280): Absence of fine and sharp appearance of brows, nose, lips, mouth, and chin, usually because of rounded and heavy features or thickened skin with or without thickening of subcutaneous and bony tissues. Evidence: PCS. Frequency: 1/1. (PMID:30187681)
- Flat face (HP:0012368): Absence of concavity or convexity of the face when viewed in profile. Evidence: PCS. Frequency: 1/1. (PMID:30187681)
- Developmental stagnation (HP:0007281): A cessation of the development of a child in the areas of motor skills, speech and language, cognitive skills, and social and/or emotional skills. Evidence: TAS. (OMIM:230600)
- Failure to thrive (HP:0001508): Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm. Evidence: PCS. Frequency: 1/1. (PMID:30187681)
- Childhood onset (HP:0011463): Onset of disease at the age of between 1 and 5 years. Evidence: PCS. Frequency: 1/1. (PMID:30187681)
- Ventriculomegaly (HP:0002119): An increase in size of the ventricular system of the brain. Evidence: IEA. (OMIM:230600)
- Hypoplastic vertebral bodies (HP:0008479). Evidence: PCS. Frequency: 1/1. (PMID:30187681)
- Patent ductus arteriosus (HP:0001643): In utero, the ductus arteriosus (DA) serves to divert ventricular output away from the lungs and toward the placenta by connecting the main pulmonary artery to the descending aorta. A patent ductus arteriosus (PDA) in the first 3 days of life is a physiologic shunt in healthy term and preterm newborn infants, and normally is substantially closed within about 24 hours after bith and completely closed after about three weeks. Failure of physiologcal closure is referred to a persistent or patent ductus arteriosus (PDA). Depending on the degree of left-to-right shunting, PDA can have clinical consequences. Evidence: PCS. Frequency: 1/1. (PMID:30187681)
- Gingival overgrowth (HP:0000212): Hyperplasia of the gingiva (that is, a thickening of the soft tissue overlying the alveolar ridge. The degree of thickening ranges from involvement of the interdental papillae alone to gingival overgrowth covering the entire tooth crown. Evidence: PCS. Frequency: 1/1. (PMID:30187681)
- Thin bony cortex (HP:0002753): Abnormal thinning of the cortical region of bones. Evidence: PCS. Frequency: 1/1. (PMID:30187681)
- Splenomegaly (HP:0001744): Abnormal increased size of the spleen. Evidence: PCS. Frequency: 0/1. (PMID:30187681)
- Premature birth (HP:0001622): The birth of a baby of less than 37 weeks of gestational age. Evidence: PCS. Frequency: 1/1. (PMID:30187681)
- Spastic tetraplegia (HP:0002510): Spastic paralysis affecting all four limbs. Evidence: IEA. (OMIM:230600)
- Limb undergrowth (HP:0009826): Limb shortening because of underdevelopment of one or more bones of the extremities. Evidence: PCS. Frequency: 1/1. (PMID:30187681)
- Dysphagia (HP:0002015): Difficulty in swallowing. Evidence: PCS. Frequency: 1/1. (PMID:30187681)
- Cerebral atrophy (HP:0002059): Atrophy (wasting, decrease in size of cells or tissue) affecting the cerebrum. Evidence: IEA. (OMIM:230600)
- Sea-blue histiocytosis (HP:0001982): An abnormality of histiocytes, in which the cells take on a sea blue appearance due to abnormally increased lipid content. Histiocytes are a type of macrophage. Sea-blue histiocytes are typically large macrophages from 20 to 60 micrometers in diameter with a single eccentric nucleus whose cytoplasm if packed with sea-blue or blue-green granules when stained with Wright-Giemsa. Evidence: IEA. (OMIM:230600)
- Scoliosis (HP:0002650): The presence of an abnormal lateral curvature of the spine. Evidence: PCS. Frequency: 1/1. (PMID:30187681)
- Joint stiffness (HP:0001387): Joint stiffness is a perceived sensation of tightness in a joint or joints when attempting to move them after a period of inactivity. Joint stiffness typically subsides over time. Evidence: PCS. Frequency: 1/1. (PMID:30187681)
- Gait disturbance (HP:0001288): The term gait disturbance can refer to any disruption of the ability to walk. Evidence: PCS. Frequency: 1/1. (PMID:30187681)
- Coxa valga (HP:0002673): Coxa valga is a deformity of the hip in which the angle between the femoral shaft and the femoral neck is increased compared to age-adjusted values (about 150 degrees in newborns gradually reducing to 120-130 degrees in adults). Evidence: IEA. (OMIM:230600)
- Progressive psychomotor deterioration (HP:0007272). Evidence: IEA. (OMIM:230600)
- Motor regression (HP:0033044): Loss of previously achieved motor skills, as manifested by loss of developmental motor milestones. Evidence: PCS. Frequency: 1/1. (PMID:30187681)
- Platyspondyly (HP:0000926): A flattened vertebral body shape with reduced distance between the vertebral endplates. Evidence: IEA. (OMIM:230600)
- Decreased beta-galactosidase activity (HP:0008166): Abnormally decreased rate of beta-galactosidase activity. Beta-galactosidase activity can be measured in leukocyte, fibroblast, or plasma. Evidence: PCS. Frequency: 1/1. (PMID:30187681)
- Dysostosis multiplex (HP:0000943). Evidence: PCS. Frequency: 1/1. (PMID:30187681)
- Thoracolumbar kyphosis (HP:0005619): Hyperconvexity of the thoracolumbar spine producing a rounded or humped appearance. Evidence: PCS. Frequency: 1/1. (PMID:30187681)
- Autosomal recessive inheritance (HP:0000007): A mode of inheritance that is observed for traits related to a gene encoded on one of the autosomes (i.e., the human chromosomes 1-22) in which a trait manifests in individuals with two pathogenic alleles, either homozygotes (two copies of the same mutant allele) or compound heterozygotes (whereby each copy of a gene has a distinct mutant allele). Evidence: IEA. (OMIM:230600)
- Optic atrophy (HP:0000648): Atrophy of the optic nerve. Optic atrophy results from the death of the retinal ganglion cell axons that comprise the optic nerve and manifesting as a pale optic nerve on fundoscopy. Evidence: IEA. (OMIM:230600)
- Beaking of vertebral bodies (HP:0004568): Anterior tongue-like protrusions of the vertebral bodies. Evidence: PCS. Frequency: 1/1. (PMID:30187681)