- Decreased circulating T4 concentration (HP:0031507): A reduction below the normal concentration of thyroxine in the blood. Thyroxine (also known as T4) is the main hormone secreted by the thyroid gland into the blood. It can be converted into the active form triiodothyronine (also known as T3). Evidence: PCS. Frequency: 3/3. (PMID:1971148)
- 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: 1/3. (PMID:1971148)
- Wide anterior fontanel (HP:0000260): Enlargement of the anterior fontanelle with respect to age-dependent norms. Evidence: PCS. Frequency: 2/3. (PMID:1971148)
- 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:275100)
- Infantile onset (HP:0003593): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. Frequency: 3/3. (PMID:1971148)
- Motor delay (HP:0001270): A type of Developmental delay characterized by a delay in acquiring motor skills. Evidence: PCS. Frequency: 1/3. (PMID:1971148)
- Depressed nasal bridge (HP:0005280): Posterior positioning of the nasal root in relation to the overall facial profile for age. Evidence: PCS. Frequency: 2/3. (PMID:1971148)
- Severe intellectual disability (HP:0010864): Severe intellectual disability (ID) is defined as a type of ID characterized by severely sub-average adaptive functioning and intellectual functioning, with an intelligence quotient (IQ) the range of 20-34. Evidence: TAS. (OMIM:275100)
- Dry skin (HP:0000958): Skin characterized by the lack of natural or normal moisture. Evidence: PCS. Frequency: 1/3. (PMID:1971148)
- Decreased thyroid-stimulating hormone level (HP:0031098): Reduced amount of the thyroid-stimulating hormone (TSH), which is produced by the anterior pituitary gland and stimulates the function of the thyroid gland. Evidence: PCS. Frequency: 3/3. (PMID:1971148)
- Umbilical hernia (HP:0001537): Protrusion of abdominal contents through a defect in the abdominal wall musculature around the umbilicus. Skin and subcutaneous tissue overlie the defect. Evidence: IEA. (OMIM:275100)
- 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:1971148)
- Hypothyroidism (HP:0000821): Deficiency of thyroid hormone. Evidence: PCS. Frequency: 3/3. (PMID:1971148)
- Severe postnatal growth retardation (HP:0008850): Severely slow or limited growth after birth, being four standard deviations or more below age- and sex-related norms. Evidence: TAS. (OMIM:275100)
- Omphalocele (HP:0001539): A midline anterior incomplete closure of the abdominal wall in which there is herniation of the abdominal viscera into the base of the abdominal cord. Evidence: PCS. Frequency: 1/3. (PMID:1971148)
- Hoarse cry (HP:0001615). Evidence: PCS. Frequency: 2/3. (PMID:1971148)
- Macroglossia (HP:0000158): Increased length and width of the tongue. Evidence: PCS. Frequency: 2/3. (PMID:1971148)
- Intellectual disability (HP:0001249): The term intellectual disability or intellectual developmental disorder is used to describe significantly sub-average intellectual and adaptive functioning based on clinical assessment and as measured by individually administered, appropriately normed, standardized and validated tests of intellectual functioning and adaptive behavior, with onset during the developmental period from infancy through adolescence. Evidence: IEA. (OMIM:275100)
These phenotypes are associated with the disease isolated thyroid-stimulating hormone deficiency (OMIM:275100).