Bone and Connective Tissue Disorders

A child presents with soft, velvety, hyperextensible skin that bruises easily. She has "cigarette paper" scars from minor trauma. Joint hypermobility is present.

A 25-year-old woman presents with chronic joint pain and recurrent dislocations. She has soft, mildly stretchy skin and scores 7/9 on the Beighton scale. She also reports POTS-like symptoms and functional GI issues.

A neonate with marked muscle hypotonia and severe joint hypermobility develops progressive kyphoscoliosis over the first year. Sclerae are blue, skin is hyperextensible, and there's a history of microcornea on eye exam. A vascular event (arterial rupture) in adolescence is the family's biggest worry.

A newborn with Pierre Robin sequence (micrognathia, glossoptosis, cleft palate) fails the newborn hearing screen. Eye exam reveals vitreous abnormalities. Family history reveals a parent with retinal detachment and early arthritis.

A 30-year-old woman presents with sudden abdominal pain. CT reveals a spontaneous sigmoid colon perforation. She has thin, translucent skin with visible veins and a history of a spontaneous arterial dissection.

A prenatal ultrasound at 28 weeks shows shortened long bones (rhizomelic shortening) with a relatively large head and frontal bossing. Parents are average height.

A newborn has bowed femora and tibiae, a bell-shaped chest with short ribs, micrognathia with cleft palate, hypoplastic scapulae, and respiratory distress within hours of birth. External genitalia appear female. Karyotype returns **46,XY**. Skeletal survey shows **11 pairs of ribs**, small scapulae, and angulated long bones.

A child can bring his shoulders together in front of his chest ("opposing shoulders"). He has a large head with frontal bossing, delayed closure of fontanelles, and multiple dental abnormalities.

A neonate has short-limbed short stature with rhizomelic limb shortening, thumbs that stick out abducted from the hand ("hitchhiker thumbs"), and ears that quickly become swollen and develop a calcified, cauliflower appearance. Cleft palate is present. Within months, severe joint contractures and progressive scoliosis develop.

A 5-year-old presents for evaluation of short stature (–2 SD). On exam, limbs appear mildly short relative to trunk, hands are short, and lumbar lordosis is mildly increased. Skull and facial features are normal (no frontal bossing, no macrocephaly). Father is also short with similar proportions and was never diagnosed.

A 10-year-old girl with short stature has mesomelic limb shortening (forearms and lower legs) and a visible wrist deformity (Madelung deformity).

A prenatal ultrasound reveals severe limb shortening, a narrow chest, and macrocephaly with a cloverleaf skull. Polyhydramnios is present. The pregnancy is complicated by hydrops.

A neonate presents with severe skeletal undermineralization, respiratory distress, and hypercalcemia. Alkaline phosphatase level is very low. The baby has "punched out" lesions on skull X-ray.

A newborn has multiple fractures noted at birth, including healing rib fractures suggesting prenatal injury. The baby has blue sclerae. Family history reveals the father has had multiple fractures and hearing loss.

A newborn has long, slender fingers (arachnodactyly), multiple joint contractures, and "crumpled" ears. The baby has a Marfanoid appearance but no lens dislocation.

A 10-year-old boy has multiple bony lumps near the ends of his long bones, particularly around the knees. X-rays show multiple osteochondromas. His father has similar lesions.

A 9-year-old is referred for recurrent knee dislocations. The thumbnails are small and split with triangular lunulae, the fifth fingernails look normal, and the elbows do not fully extend. A pelvic radiograph ordered for hip pain shows bilateral conical bony projections off the posterior iliac wings. Urinalysis shows 2+ protein.

A child has disproportionate **short-trunk** short stature, severely restricted joint motion with prominent knees and elbows, midface hypoplasia with cleft palate, **high myopia**, and progressive sensorineural hearing loss. Skeletal survey shows dumbbell-shaped femora; cartilage histology shows a "Swiss cheese" appearance.

A neonate is born with **symmetric tetraphocomelia** (severe shortening of all four limbs with hands and feet attached close to the trunk), bilateral cleft lip and palate, microcephaly, and a midfacial capillary hemangioma. Karyotype with standard Giemsa staining shows the diagnostic finding: **premature centromere separation** with characteristic **"railroad track" appearance** of chromosomes and "puffing" of heterochromatic regions.