- Bilateral tonic-clonic seizure (HP:0002069): A bilateral tonic-clonic seizure is a seizure defined by a tonic (bilateral increased tone, lasting seconds to minutes) and then a clonic (bilateral sustained rhythmic jerking) phase. Evidence: PCS. Frequency: 1/2. (PMID:33386993)
- 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: 1/2. (PMID:33386993)
- Congenital onset (HP:0003577): A phenotypic abnormality that is present at birth. Evidence: PCS. Frequency: 2/2. (PMID:33386993)
- 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: PCS. Frequency: 1/2. (PMID:33386993)
- 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: 1/2. (PMID:33386993)
- Short nose (HP:0003196): Distance from nasion to subnasale more than two standard deviations below the mean, or alternatively, an apparently decreased length from the nasal root to the nasal tip. Evidence: PCS. Frequency: 1/2. (PMID:33386993)
- 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: 1/2. (PMID:33386993)
- 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: PCS. Frequency: 2/2. (PMID:33386993)
- Hypoplastic thumbnail (HP:0012553): A thumbnail that is diminished in length and width, i.e., underdeveloped thumb nail. Evidence: PCS. Frequency: 2/2. (PMID:33386993)
- Hypoplastic fingernail (HP:0001804): Underdevelopment of a fingernail. Evidence: PCS. Frequency: 1/2. (PMID:33386993)
- Hypoplastic fifth fingernail (HP:0008398): A nail of the fifth finger that is diminished in length and width, i.e., underdeveloped nail of little finger. Evidence: PCS. Frequency: 2/2. (PMID:33386993)
- Short distal phalanx of finger (HP:0009882): Short distance from the end of the finger to the most distal interphalangeal crease or the distal interphalangeal joint flexion point. That is, hypoplasia of one or more of the distal phalanx of finger. Evidence: PCS. Frequency: 1/2. (PMID:33386993)
- Hypoplastic toenails (HP:0001800): Underdevelopment of the toenail. Evidence: PCS. Frequency: 2/2. (PMID:33386993)
- Bilateral triphalangeal thumbs (HP:0005707): A bilateral form of triphalangeal thumb. Evidence: PCS. Frequency: 1/2. (PMID:33386993)
- Delayed eruption of permanent teeth (HP:0000696): Delayed tooth eruption affecting the secondary dentition. Evidence: PCS. Frequency: 1/2. (PMID:33386993)
- Abnormality of alkaline phosphatase level (HP:0004379): An abnormality of alkaline phosphatase level. Evidence: PCS. Frequency: 0/2. (PMID:33386993)
- Microcephaly (HP:0000252): Head circumference below 2 standard deviations below the mean for age and gender. Evidence: PCS. Frequency: 1/2. (PMID:33386993)
- Absent speech (HP:0001344): Complete lack of development of speech and language abilities. Evidence: PCS. Frequency: 1/2. (PMID:33386993)
- Open mouth (HP:0000194): A facial appearance characterized by a permanently or nearly permanently opened mouth. Evidence: PCS. Frequency: 1/2. (PMID:33386993)
- 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: PCS. Frequency: 2/2. (PMID:33386993)
- Microdontia (HP:0000691): Decreased size of the teeth, which can be defined as a mesiodistal tooth diameter (width) more than 2 SD below mean. Alternatively, an apparently decreased maximum width of tooth. Evidence: PCS. Frequency: 1/2. (PMID:33386993)
- Absent fifth toenail (HP:0200105). Evidence: PCS. Frequency: 1/2. (PMID:33386993)
- Impaired toileting ability (HP:0031061): This term applies to an individual who requires help transferring to the toilet, cleaning self or who uses bedpan or commode. Evidence: PCS. Frequency: 1/2. (PMID:33386993)
- Head-banging (HP:0012168): Habitual striking of one's own head against a surface such as a mattress or wall of a crib. Evidence: PCS. Frequency: 1/2. (PMID:33386993)
- Precocious puberty (HP:0000826): The onset of secondary sexual characteristics before a normal age. Although it is difficult to define normal age ranges because of the marked variation with which puberty begins in normal children, precocious puberty can be defined as the onset of puberty before the age of 8 years in girls or 9 years in boys. Evidence: PCS. Frequency: 1/2. (PMID:33386993)
- 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:33386993)
- Short distal phalanx of toe (HP:0001857): Short distance from the end of the toe to the most distal interphalangeal crease or distal interphalangeal joint flexion point, i.e., abnormally short distal phalanx of toe. Evidence: PCS. Frequency: 1/2. (PMID:33386993)
- Atrial septal defect (HP:0001631): Atrial septal defect (ASD) is a congenital abnormality of the interatrial septum that enables blood flow between the left and right atria via the interatrial septum. Evidence: PCS. Frequency: 1/2. (PMID:33386993)
- Micrognathia (HP:0000347): Developmental hypoplasia of the mandible. Evidence: PCS. Frequency: 1/2. (PMID:33386993)
These phenotypes are associated with the disease onychodystrophy, osteodystrophy, impaired intellectual development, and seizures syndrome (OMIM:619356).