- Decreased body weight (HP:0004325): Abnormally low body weight. Evidence: IEA. (OMIM:300580)
- Polyhydramnios (HP:0001561): The presence of excess amniotic fluid in the uterus during pregnancy. Evidence: IEA. (OMIM:300580)
- Generalized neonatal hypotonia (HP:0008935): Muscular hypotonia (abnormally low muscle tone) manifesting in the neonatal period and affecting the entire musculature. Evidence: TAS. (OMIM:300580)
- 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: TAS. (OMIM:300580)
- Congenital onset (HP:0003577): A phenotypic abnormality that is present at birth. Evidence: PCS. (PMID:16173074)
- Short stature (HP:0004322): A height below that which is expected according to age and gender norms. Although there is no universally accepted definition of short stature, many refer to "short stature" as height more than 2 standard deviations below the mean for age and gender (or below the 3rd percentile for age and gender dependent norms). Evidence: IEA. (OMIM:300580)
- Respiratory distress (HP:0002098): Respiratory distress is objectively observable as the physical or emotional consequences from the experience of dyspnea. The physical presentation of respiratory distress is generally referred to as labored breathing, while the sensation of respiratory distress is called shortness of breath or dyspnea. Evidence: TAS. (OMIM:300580)
- Myopathy (HP:0003198): A disorder of muscle unrelated to impairment of innervation or neuromuscular junction. Evidence: TAS. (OMIM:300580)
- Poor suck (HP:0002033): An inadequate sucking reflex, resulting in the difficult of newborns to be breast-fed. Evidence: IEA. (OMIM:300580)
- Frontalis muscle weakness (HP:0004661): Reduced strength of the frontalis muscle (which is located on the forehead). Evidence: IEA. (OMIM:300580)
- 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:300580)
- Respiratory insufficiency due to muscle weakness (HP:0002747). Evidence: IEA. (OMIM:300580)
- X-linked dominant inheritance (HP:0001423): A mode of inheritance that is observed for dominant traits related to a gene encoded on the X chromosome. In the context of medical genetics, X-linked dominant disorders tend to manifest very severely in affected males. The severity of manifestation in females may depend on the degree of skewed X inactivation. Evidence: PCS. (PMID:16173074)
- Weak cry (HP:0001612). Evidence: IEA. (OMIM:300580)
- Micrognathia (HP:0000347): Developmental hypoplasia of the mandible. Evidence: IEA. (OMIM:300580)
- Type 1 fibers relatively smaller than type 2 fibers (HP:0003755): The presence of abnormal muscle fiber size such that type 1 fibers are smaller than type 2 fibers. Evidence: TAS. (OMIM:300580)
- Dilated cardiomyopathy (HP:0001644): Dilated cardiomyopathy (DCM) is defined by the presence of left ventricular dilatation and left ventricular systolic dysfunction in the absence of abnormal loading conditions (hypertension, valve disease) or coronary artery disease sufficient to cause global systolic impairment. Right ventricular dilation and dysfunction may be present but are not necessary for the diagnosis. Evidence: IEA. (OMIM:300580)
These phenotypes are associated with the disease myopathy, congenital, with fiber-type disproportion, X-linked (OMIM:300580).