- Flared metaphysis (HP:0003015): The presence of a splayed (i.e.,flared) metaphyseal segment of one or more long bones. Evidence: IEA. (OMIM:259700)
- Facial palsy (HP:0010628): Facial nerve palsy is a dysfunction of cranial nerve VII (the facial nerve) that results in inability to control facial muscles on the affected side with weakness of the muscles of facial expression and eye closure. This can either be present in unilateral or bilateral form. Evidence: IEA. (OMIM:259700)
- Cranial nerve paralysis (HP:0006824). Evidence: PCS. Frequency: 1/5. (PMID:10888887)
- Femur fracture (HP:0031846): A break or crush injury of the thigh bone (femur). Evidence: PCS. Frequency: 1/1. (PMID:34210262)
- Hearing impairment (HP:0000365): A decreased magnitude of the sensory perception of sound. Evidence: IEA. (OMIM:259700)
- 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:259700)
- Elevated circulating alkaline phosphatase concentration (HP:0003155): Abnormally increased serum levels of alkaline phosphatase activity. Evidence: PCS. Frequency: 11/11. (OMIM:259700;PMID:34210262)
- Hepatomegaly (HP:0002240): Abnormally increased size of the liver. Evidence: PCS. Frequency: 5/5. (PMID:10888887)
- Infantile onset (HP:0003593): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. Frequency: 5/5. (PMID:10888887)
- Calvarial osteosclerosis (HP:0005450): An increase in bone density affecting the calvaria (roof of the skull). Evidence: PCS. Frequency: 1/1. (PMID:34210262)
- Failure to thrive (HP:0001508): Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm. Evidence: IEA. (OMIM:259700)
- Nystagmus (HP:0000639): Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms. Evidence: IEA. (OMIM:259700)
- Osteopetrosis (HP:0011002): Abnormally increased formation of dense trabecular bone tissue. Despite the increased density of bone tissue, osteopetrotic bones tend to be more fracture-prone than normal. Evidence: PCS. Frequency: 11/11. (PMID:34210262;PMID:10888887)
- Anemia (HP:0001903): A reduction in erythrocytes volume or hemoglobin concentration. Evidence: PCS. Frequency: 3/6. (PMID:34210262;PMID:10888887)
- Increased bone mineral density (HP:0011001): An abnormal increase of bone mineral density, that is, of the amount of matter per cubic centimeter of bones which is often referred to as osteosclerosis. Osteosclerosis can be detected on radiological examination as an increased whiteness (density) of affected bones. Evidence: PCS. Frequency: 1/1. (PMID:34210262)
- Blindness (HP:0000618): Blindness is the condition of lacking visual perception defined as a profound reduction in visual perception. On the 6m visual acuity scale, blindness is defined as less than 3/60. On the 20ft visual acuity scale, blindness is defined as less than 20/400. On the decimal visual acuity scale, blindness is defined as less than 0.05. Blindness is typically characterized by a visual field of no greater than 10 degrees in radius around central fixation. Evidence: IEA. (OMIM:259700)
- 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: PCS. Frequency: 1/5. (PMID:10888887)
- Sandwich appearance of vertebral bodies (HP:0004618). Evidence: IEA. (OMIM:259700)
- Coxa vara (HP:0002812): Coxa vara includes all forms of decrease of the femoral neck shaft angle (the angle between the neck and the shaft of the femur) to less than 120 degrees. Evidence: IEA. (OMIM:259700)
- Increased circulating lactate dehydrogenase concentration (HP:0025435): An elevated level of the enzyme lactate dehydrogenase in the blood circulation. Evidence: PCS. Frequency: 1/1. (PMID:34210262)
- Macrocephaly (HP:0000256): Occipitofrontal (head) circumference greater than 97th centile compared to appropriate, age matched, sex-matched normal standards. Alternatively, a apparently increased size of the cranium. Evidence: PCS. Frequency: 2/6. (PMID:34210262;PMID:10888887)
- Ophthalmoparesis (HP:0000597): Ophthalmoplegia is a paralysis or weakness of one or more of the muscles that control eye movement. Evidence: IEA. (OMIM:259700)
- Pathologic fracture (HP:0002756): A pathologic fracture occurs when a bone breaks in an area that is weakened secondarily to another disease process such as tumor, infection, and certain inherited bone disorders. A pathologic fracture can occur without a degree of trauma required to cause fracture in healthy bone. Evidence: IEA. (OMIM:259700)
- Splenomegaly (HP:0001744): Abnormal increased size of the spleen. Evidence: PCS. Frequency: 5/5. (PMID:10888887)
- Osteomyelitis (HP:0002754): Osteomyelitis is an inflammatory process accompanied by bone destruction and caused by an infecting microorganism. Evidence: IEA. (OMIM:259700)
- Carious teeth (HP:0000670): Caries is a multifactorial bacterial infection affecting the structure of the tooth. This term has been used to describe the presence of more than expected dental caries. Evidence: IEA. (OMIM:259700)
- Facial paralysis (HP:0007209): Complete loss of ability to move facial muscles innervated by the facial nerve (i.e., the seventh cranial nerve). Evidence: TAS. (OMIM:259700)
- Craniosynostosis (HP:0001363): Craniosynostosis refers to the premature closure of the cranial sutures. Primary craniosynostosis refers to the closure of one or more sutures due to abnormalities in skull development, and secondary craniosynostosis results from failure of brain growth. Evidence: PCS. Frequency: 1/1. (PMID:34210262)
- Tetany (HP:0001281): A condition characterized by intermittent involuntary contraction of muscles (spasms) related to hypocalcemia or occasionally magnesium deficiency. Evidence: IEA. (OMIM:259700)
- 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: PCS. (PMID:10888887)
- 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: PCS. Frequency: 1/5. (PMID:10888887)
- Visual impairment (HP:0000505): Visual impairment (or vision impairment) is vision loss (of a person) to such a degree as to qualify as an additional support need through a significant limitation of visual capability resulting from either disease, trauma, or congenital or degenerative conditions that cannot be corrected by conventional means, such as refractive correction, medication, or surgery. Evidence: PCS. Frequency: 2/5. (PMID:10888887)
- Hypocalcemia (HP:0002901): The concentration of calcium in the blood circulation is below the lower limit of normal. Evidence: PCS. Frequency: 3/6. (PMID:34210262;PMID:10888887)
- Frontal bossing (HP:0002007): Bilateral bulging of the lateral frontal bone prominences with relative sparing of the midline. Evidence: IEA. (OMIM:259700)
- Thrombocytopenia (HP:0001873): A reduction in the number of circulating thrombocytes. Evidence: PCS. Frequency: 2/5. (PMID:10888887)
- Pancytopenia (HP:0001876): An abnormal reduction in numbers of all blood cell types (red blood cells, white blood cells, and platelets). Evidence: IEA. (OMIM:259700)
These phenotypes are associated with the disease autosomal recessive osteopetrosis 1 (OMIM:259700).