- Opisthotonus (HP:0002179): Opisthotonus is defined as a dramatic abnormal posture due to spastic contraction of the extensor muscles of the neck, trunk, and lower extremities that produces a severe backward arching from neck to heel. In most cases, the trunk is elevated off the ground by a few inches. It is usually sudden in onset and can be sustained or repetitive. It can be considered a variant of decerebrate posturing involving a hyperextension of the neck, back, and limbs. Evidence: PCS. Frequency: 2/2. (PMID:34037727)
- Poor head control (HP:0002421): Difficulty to maintain correct position of the head while standing or sitting. Infant head lag is observed when the head seems to flop around or lags posteriorly behind the trunk. Several articles have maintained that head lag should be absent by age 3 to 4 months. Evidence: PCS. Frequency: 2/2. (PMID:34037727)
- Elevated circulating aspartate aminotransferase concentration (HP:0031956): The concentration of aspartate aminotransferase (AST) in the blood circulation is above the upper limit of normal. Evidence: PCS. Frequency: 2/2. (PMID:34037727)
- Hypoplasia of the corpus callosum (HP:0002079): Underdevelopment of the corpus callosum. Evidence: PCS. Frequency: 2/2. (PMID:34037727)
- Cerebellar atrophy (HP:0001272): Cerebellar atrophy is defined as a cerebellum with initially normal structures, in a posterior fossa with normal size, which displays enlarged fissures (interfolial spaces) in comparison to the foliae secondary to loss of tissue. Cerebellar atrophy implies irreversible loss of tissue and result from an ongoing progressive disease until a final stage is reached or a single injury, e.g. an intoxication or infectious event. Evidence: PCS. Frequency: 1/2. (PMID:34037727)
- Feeding difficulties (HP:0011968): Impaired ability to eat related to problems gathering food and getting ready to suck, chew, or swallow it. Evidence: PCS. Frequency: 2/2. Onset: Neonatal onset (HP:0003623). (PMID:34037727)
- Generalized tonic seizure (HP:0010818): A generalized tonic seizure is a type of generalized motor seizure characterized by bilateral limb stiffening or elevation, often with neck stiffening without a subsequent clonic phase. The tonic activity can be a sustained abnormal posture, either in extension or flexion, sometimes accompanied by tremor of the extremities. Evidence: PCS. Frequency: 1/2. (PMID:34037727)
- Secondary microcephaly (HP:0005484): Head circumference which falls below 2 standard deviations below the mean for age and gender because of insufficient head growth after birth. Evidence: PCS. Frequency: 1/2. (PMID:34037727)
- Severe global developmental delay (HP:0011344): A severe delay in the achievement of motor or mental milestones in the domains of development of a child. Evidence: PCS. Frequency: 2/2. (PMID:34037727)
- High myopia (HP:0011003): A severe form of myopia with greater than -6.00 diopters. Evidence: PCS. Frequency: 1/2. (PMID:34037727)
- Increased serum bile acid concentration (HP:0012202): An increase in the concentration of bile acid in the blood. Evidence: PCS. Frequency: 1/2. (PMID:34037727)
- Elevated circulating alanine aminotransferase concentration (HP:0031964): An abnormally high concentration in the circulation of alanine aminotransferase (ALT). Evidence: PCS. Frequency: 2/2. (PMID:34037727)
- Mild proteinuria (HP:0012595): Mildly increased levels of protein in the urine (150-500 mg per day in adults). Evidence: PCS. Frequency: 1/2. (PMID:34037727)
- Death in childhood (HP:0003819): Death in during childhood, defined here as between the ages of 2 and 10 years. Evidence: PCS. Frequency: 1/2. (PMID:34037727)
- Irritability (HP:0000737): An emotional state characterized by negative feelings of heightened frustration, annoyance, or feeling upset, often triggered by internal factors (e.g., fatigue, hunger, unfulfilled desires) or external factors (e.g., social or environmental challenges). Irritability may be unpredictable, and is accompanied by a lowered threshold for emotional reactivity and observable features (speech, facial expressions, or psychomotor activity). Evidence: PCS. Frequency: 2/2. (PMID:34037727)
- Hyperbilirubinemia (HP:0002904): An increased amount of bilirubin in the blood. Evidence: PCS. Frequency: 2/2. Onset: Neonatal onset (HP:0003623). (PMID:34037727)
- Nasogastric tube feeding (HP:0040288): The condition of inability to eat normally treated by placement of a thin tube through the nose into the stomach that is then used to carry food. Evidence: PCS. Frequency: 1/2. (PMID:34037727)
- 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:34037727)
- Esodeviation (HP:0020045): A manifest or latent ocular deviation in which one or both eyes tends to deviate nasally. Evidence: PCS. Frequency: 1/2. (PMID:34037727)
- Intrahepatic cholestasis (HP:0001406): Impairment of bile flow due to obstruction in the small bile ducts within the liver. Evidence: PCS. Frequency: 1/2. (PMID:34037727)
- Bilateral cryptorchidism (HP:0008689): Absence of both testes from the scrotum owing to failure of the testis or testes to descend through the inguinal canal to the scrotum. Evidence: PCS. Frequency: 1/2. (PMID:34037727)
- Neonatal onset (HP:0003623): Onset of signs or symptoms of disease within the first 28 days of life. Evidence: PCS. Frequency: 2/2. (PMID:34037727)
These phenotypes are associated with the disease neurodevelopmental disorder with microcephaly, seizures, and neonatal cholestasis (OMIM:619685).