- Epicanthus (HP:0000286): A fold of skin starting above the medial aspect of the upper eyelid and arching downward to cover, pass in front of and lateral to the medial canthus. Evidence: IEA. (OMIM:269920)
- Nephrotic syndrome (HP:0000100): Nephrotic syndrome is a collection of findings resulting from glomerular dysfunction with an increase in glomerular capillary wall permeability associated with pronounced proteinuria. Nephrotic syndrome refers to the constellation of clinical findings that result from severe renal loss of protein, with Proteinuria and hypoalbuminemia, edema, and hyperlipidemia. Evidence: IEA. (OMIM:269920)
- Anteverted nares (HP:0000463): Anteriorly-facing nostrils viewed with the head in the Frankfurt horizontal and the eyes of the observer level with the eyes of the subject. This gives the appearance of an upturned nose (upturned nasal tip). Evidence: IEA. (OMIM:269920)
- Seizure (HP:0001250): A seizure is an intermittent abnormality of nervous system physiology characterized by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain. Evidence: IEA. (OMIM:269920)
- Fair hair (HP:0002286): A lesser degree of hair pigmentation than would otherwise be expected. Evidence: IEA. (OMIM:269920)
- Hypopigmentation of the skin (HP:0001010): A reduction of skin color related to a decrease in melanin production and deposition. Evidence: IEA. (OMIM:269920)
- Hypotonia (HP:0001252): Hypotonia is an abnormally low muscle tone (the amount of tension or resistance to movement in a muscle). Even when relaxed, muscles have a continuous and passive partial contraction which provides some resistance to passive stretching. Hypotonia thus manifests as diminished resistance to passive stretching. Hypotonia is not the same as muscle weakness, although the two conditions can co-exist. Evidence: IEA. (OMIM:269920)
- Hepatomegaly (HP:0002240): Abnormally increased size of the liver. Evidence: IEA. (OMIM:269920)
- J-shaped sella turcica (HP:0002680): A deformity of the sella turcica whereby the sella extends further anterior than normal such that the anterior clinoid process appears to overhang it, giving the appearance of the letter J on imaging of the skull. Evidence: IEA. (OMIM:269920)
- Generalized hypotonia (HP:0001290): Generalized muscular hypotonia (abnormally low muscle tone). Evidence: TAS. (OMIM:269920)
- 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: IEA. (OMIM:269920)
- Nystagmus (HP:0000639): Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms. Evidence: IEA. (OMIM:269920)
- Failure to thrive (HP:0001508): Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm. Evidence: IEA. (OMIM:269920)
- Osteopenia (HP:0000938): Osteopenia is a term to define bone density that is not normal but also not as low as osteoporosis. By definition from the World Health Organization osteopenia is defined by bone densitometry as a T score -1 to -2.5. Evidence: IEA. (OMIM:269920)
- Vacuolated lymphocytes (HP:0001922): The presence of clear, sharply defined vacuoles in the lymphocyte cytoplasm. Evidence: IEA. (OMIM:269920)
- Hydrocephalus (HP:0000238): Hydrocephalus is an active distension of the ventricular system of the brain resulting from inadequate passage of CSF from its point of production within the cerebral ventricles to its point of absorption into the systemic circulation. Evidence: IEA. (OMIM:269920)
- Hydrops fetalis (HP:0001789): The abnormal accumulation of fluid in two or more fetal compartments, including ascites, pleural effusion, pericardial effusion, and skin edema. Evidence: IEA. (OMIM:269920)
- High palate (HP:0000218): Height of the palate more than 2 SD above the mean (objective) or palatal height at the level of the first permanent molar more than twice the height of the teeth (subjective). Evidence: IEA. (OMIM:269920)
- 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: IEA. (OMIM:269920)
- Splenomegaly (HP:0001744): Abnormal increased size of the spleen. Evidence: IEA. (OMIM:269920)
- Premature birth (HP:0001622): The birth of a baby of less than 37 weeks of gestational age. Evidence: IEA. (OMIM:269920)
- Abnormal foot morphology (HP:0001760): An abnormality of the skeleton of foot. Evidence: IEA. (OMIM:269920)
- Cerebral atrophy (HP:0002059): Atrophy (wasting, decrease in size of cells or tissue) affecting the cerebrum. Evidence: IEA. (OMIM:269920)
- Ascites (HP:0001541): Accumulation of fluid in the peritoneal cavity (between the layers of the peritoneum that lines the abdomen). Evidence: IEA. (OMIM:269920)
- Cardiomegaly (HP:0001640): Increased size of the heart, clinically defined as an increased transverse diameter of the cardiac silhouette that is greater than or equal to 50% of the transverse diameter of the chest (increased cardiothoracic ratio) on a posterior-anterior projection of a chest radiograph or a computed tomography. Evidence: IEA. (OMIM:269920)
- Metaphyseal irregularity (HP:0003025): Irregularity of the normally smooth surface of the metaphyses. Evidence: IEA. (OMIM:269920)
- Global developmental delay (HP:0001263): A delay in the achievement of motor or mental milestones in the domains of development of a child, including motor skills, speech and language, cognitive skills, and social and emotional skills. This term should only be used to describe children younger than five years of age. Evidence: IEA. (OMIM:269920)
- Conjugated hyperbilirubinemia (HP:0002908). Evidence: IEA. (OMIM:269920)
- Death in childhood (HP:0003819): Death in during childhood, defined here as between the ages of 2 and 10 years. Evidence: IEA. (OMIM:269920)
- Ptosis (HP:0000508): The upper eyelid margin is positioned 3 mm or more lower than usual and covers the superior portion of the iris (objective); or, the upper lid margin obscures at least part of the pupil (subjective). Evidence: IEA. (OMIM:269920)
- 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:269920)
- Congestive heart failure (HP:0001635): The presence of an abnormality of cardiac function that is responsible for the failure of the heart to pump blood at a rate that is commensurate with the needs of the tissues or a state in which abnormally elevated filling pressures are required for the heart to do so. Heart failure is frequently related to a defect in myocardial contraction. Evidence: IEA. (OMIM:269920)
- Abnormal thorax morphology (HP:0000765): Any abnormality of the thorax (the region of the body formed by the sternum, the thoracic vertebrae and the ribs). Evidence: IEA. (OMIM:269920)
These phenotypes are associated with the disease free sialic acid storage disease, infantile form (OMIM:269920).