About Marshall-Smith Syndrome ("MSS")

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The following is a list of various symptoms and conditions that have been described in patients with Marshall-Smith Syndrome. 

Skull

Macrocephaly – head larger than usual

Craniosynostosis – premature closure of skull sutures

Trigonocephaly – early closure of the metopic suture

Thickened calvarium – abnormally thick skull bone

Dolichocephaly – elongated head shape

Wormian bone growth in skull sutures

Frontal bossing – forehead bone protrudes outward

Large and prominent forehead

Shallow orbits – shallow eye sockets

Midface hypoplasia – undersized bones of the cheeks, nose and upper jaw

Neck & Spine

Abnormal neck extension

Atlantoaxial (C1-C2) instability or dislocation

Congenital spinal stenosis – narrowing of space around the spinal cord

Scoliosis – sideways curvature of the spine

Kyphosis – abnormal rounding of the upper back

Kyphoscoliosis – curving of the spine side to side and front to back

Sacral dimple

Protruding sacrum/coccyx

Hands & Feet

Large, distinct hands

Bullet-shaped middle fingers

Proximal insertion of thumb – thumb is set lower on the hand

Distal widening of the metacarpals

Clinodactyly of the 5th finger – pinky finger turns inward

Prominent finger and toe pads

Hallux valgus – big toe points inward

Flexion of the great toes – hammer toe

Deep crease between big toe and second toe

Overlapping toes – toes bunch together as if crowded

Ingrown toenails

Hypoplastic fingernails and toenails

Flat feet

Long, slender feet

Miscellaneous Musculoskeletal

Hypotonia - low muscle tone throughout the body

Joint hypermobility 

Accelerated skeletal maturation

Recurrent fractures

Osteopenia/osteoporosis - decreased bone density

Asymmetrical rib cage, narrower at the top

Large sternal ossification centers

Pectus excavatum or carinatum – sternum is sunken in or protruding

Abdominal hernias (umbilical, specifically)

Decreased hip abduction

Hip dysplasia – shallow hip sockets

Coxa vara – abnormal shape of femoral neck

Bowing of the long bones

Slender bones

Tibial torsion – abnormal rotation in lower leg

Spasticity

Short adult stature

Airway

Airway obstruction, anatomical

Laryngomalacia – floppy tissue in back of throat

Tracheomalacia – floppy tissue in trachea

Bronchopulmonary Dysplasia

Stridor – high-pitched sound heard upon inhale

Obstructive sleep apnea

Aspiration pneumonia

Atelectasis – collapse of the air sacs in the lungs

Acute respiratory distress

Respiratory failure

Hypoxia – insufficient blood oxygen levels

Hypercapnia – levels of CO2 are too high

Hypopnea – shallow breathing

Tachypnea – rapid breathing

Nose & Mouth

Depressed nasal bridge

Anteverted nares – upturned nose

Choanal atresia – nasal passage is closed off by bone or tissue

Choanal stenosis – nasal passage is narrow

Underdeveloped sinus cavities

High palate

Rudimentary epiglottis

Gingival overgrowth

Irregular dentition

Microdontia – smaller than usual teeth

Delayed tooth eruption

Glossoptosis – tongue set farther back in the throat

Open or gaped mouth

Protruding tongue

Hypersalivation – drooling

Micrognathia – lower jaw is undersized

Retrognathia – lower jaw is set back more than usual

Microretrognathia – lower jaw is both undersized and set back

Skin & Hair

Thin skin - fragile and soft

Bruising susceptibility

Thick eyebrow

Synophrys – eyebrows grow together in the middle

Hypertrichosis – excessive hair growth in males and females

Hirsutism – abnormal, male-pattern hair growth in females

Ears

Low-set ears

Overfolded helix – ears have a “crumpled” appearance

Ear canal stenosis

Cholesteatoma

Frequent ear infections

Cerumen impaction – ear wax blockage in ears

Hearing loss

Eyes & Vision

Proptosis – bulging eyes

Blue sclerae – whites of the eyes have a bluish tint

Hypertelorism – widely spaced eyes

Myopia - nearsightedness

Astigmatism - abnormal shape of the cornea

Glaucoma – high intraocular pressures

Optic nerve hypoplasia – undersized optic nerves

Cortical Visual Impairment – problems with the vision centers of the brain

Keratoconus – cornea becomes thin and conical

Exophthalmos – eyes dislocate from socket

Lagophthalmos – incomplete closure of the eyes

Dry eyes

Photosensitivity – sensitivity to light

Corneal ulcer

Eye infections

Entropion – eyelid turns inward and eyelashes cause irritation

Anisocoria – benign unequal pupil size

Cardiovascular

Pulmonary arterial hypertension

Premature ventricular contraction

Dysplastic aortic valve

Patent ductus arteriosus

Atrial septal defect

Ventricular septal defect

Mitral valve stenosis

Hypertension

Small, fragile veins

Internal jugular vein outflow disturbance

Cerebral vascular anomalies

Sinus tachycardia

Gastrointestinal

Pyloric stenosis

Anteriorly placed anus

Feeding difficulties

Failure to thrive

Low body weight

Omphalocele

Choledocholithiasis

Fasting hypoglycemia

Malabsorption

GERD – reflux

Lactose intolerance

Intestinal dysmotility

Dysphagia

Vomiting of unknown etiology

Genitourinary 

Vesicoureteral reflux

Renal hypoplasia

Cryptorchidism – undescended testicle(s)

Hypospadias

Neurogenic bladder

Urinary retention

Hydronephrosis

Immunology

Recurrent infections (ear, sinus, respiratory)

Hypogammaglobulinemia – low IgG, immune deficiency

Neurological

Absence of the Septum Pellucidum

Abnormalities of the Corpus Callosum

Microgyria/Macrogyria/Pachygyria – abnormal folds on surface of the brain

Delayed myelination

Periventricular Leukomalacia

Hypoxic-Ischemic Encephalopathy (HIE)

Cerebellar hypoplasia

Brainstem hypoplasia

Cerebral atrophy

Hydrocephalus

Increased intracranial pressure (ICP)

Ventriculomegaly

Cervical cord compression

Brisk reflexes

Clonus

Heat intolerance

Developmental/Behavioral

Global developmental delay

Absent or delayed speech and language development

Intellectual disability, moderate to severe

Psychomotor delays

Autism spectrum disorder

Early onset of puberty