It involves three major defects:

- A failure of the diaphragm to completely close during development

- Herniation of the abdominal contents into the chest

- Pulmonary hypoplasia

The diagnosis of congenital diaphragmatic eventration is used when there is abnormal displacement (i.e. elevation) of part or all of an otherwise intact diaphragm into the chest cavity. This rare type of CDH occurs because in the region of eventration the diaphragm is thinner, allowing the abdominal viscera to protrude upwards.

The blockage of cerebrospinal fluid (CSF) flow may also cause a syrinx to form, eventually leading to syringomyelia. Central cord symptoms such as hand weakness, dissociated sensory loss, and, in severe cases, paralysis may occur.

Syringomyelia is a chronic progressive degenerative disorder characterized by a fluid-filled cyst located in the spinal cord. Its symptoms include pain, weakness, numbness, and stiffness in the back, shoulders, arms or legs. Other symptoms include headaches, the inability to feel changes in the temperature, sweating, sexual dysfunction, and loss of bowel and bladder control. It is usually seen in the cervical region but can extend into the medulla oblongata and pons or it can reach downward into the thoracic or lumbar segments. Syringomyelia is often associated with Chiari malformation type I and is commonly seen between the C-4 and C-6 levels. The exact development of syringomyelia is unknown but many theories suggest that the herniated tonsils in Chiari malformation type I form a "plug" which does not allow an outlet of CSF from the brain to the spinal canal. Syringomyelia is present in 25% of patients with Chiari malformation.

Numerous associated abnormalities of other organ systems may be present. This heterogeneity requires comprehensive evaluation of all patients and treatment regimes that can vary from modification of activities to extensive spinal surgeries. Furthermore, it is unclear whether Klippel–Feil syndrome is a unique disease, or if it is one part of a spectrum of congenital spinal deformities. Klippel–Feil syndrome is usually diagnosed after birth.

The most common sign of the disorder is restricted mobility of the neck and upper spine. A short neck and low hairline at the back of the head may occur in some patients.

Associated abnormalities may include:

- scoliosis (side-to-side curvature of the spine), which is abnormal curving of the spine. The spine sometimes appears as a "C" or an "S"

- spina bifida, when the spinal canal and the back bone do not close completely during birth

- anomalies of the kidneys and the ribs

- cleft palate (hole in the roof of the mouth)

- dental problems (late dentition, high-risk of caries, oligo- and hypodontia)

- respiratory problems

- heart malformations

- short stature

- Duane syndrome

- Approximately 35% of patients with Klippel–Feil syndrome will also have a congenital elevation of the scapula known as Sprengel's deformity

The disorder also may be associated with abnormalities of the head and face, skeleton, sex organs, muscles, brain and spinal cord, arms, legs, fingers and heart defects. These heart defects often lead to a shortened life expectancy, the average being 35–45 years of age among males and 40–50 among females. This condition is similar to the heart failure seen in gigantism.

In 2011, a study identifying the occurrence of symptoms of 100 patients was published.

The syndrome has five characteristic findings:

- Omphalocele

- Anterior diaphragmatic hernia

- Sternal cleft with or without ectopia cordis

- Diaphragmatic pericardium defects (no diaphragmatic pericardium)

- Intracardiac defect: ventricular septal defect, diverticulum of the left ventricle, Tetralogy of Fallot

The patient presents with a protrusion near the neck or between the ribs. The mass becomes prominent when the patient is straining or coughing. In asymptomatic individuals, lung hernia is incidentally detected in a chest X-ray taken for another reason. On physical examination, a prominence or mass is seen during Valsalva maneuver.

In normal Bochdalek hernia cases, the symptoms are often observable simultaneously with the baby's birth. A few of the symptoms of a Bochdalek Hernia include difficulty breathing, fast respiration and increased heart rate. Also, if the baby appears to have cyanosis (blue-tinted skin) this can also be a sign. Another way to differentiate a healthy baby from a baby with Bochdalek Hernia, is to look at the chest immediately after birth. If the baby has a Bochdalek Hernia it may appear that one side of the chest cavity is larger than the other and or the abdomen seems to be concave (caved in).

Klippel–Feil syndrome is a rare disease, initially reported in 1884 by Maurice Klippel and André Feil from France, characterized by the congenital fusion of any two of the seven cervical vertebrae.

The syndrome occurs in a heterogeneous group of patients unified only by the presence of a congenital defect in the formation or segmentation of the cervical spine. Klippel-Feil results in limited movement of the neck. Klippel–Feil syndrome is sometimes identified by shortness of the neck, but not all people with this disorder have a visibly shortened neck. Some people with the syndrome have a very low hairline.

In 1919, in his PhD thesis, André Feil suggested another classification of the syndrome encompassing not only deformation of the cervical spine but also deformation of the lumbar and thoracic spine.

Usually associated with diaphragmatic hernia,

pulmonary hypoplasia,

imperforate anus,

micropenis,

bilateral cryptorchidism,

cerebral ventricular dilation,

camptodactyly,

agenesis of sacrum,

low-set ear.

- Fryns et al. (1979) reported 2 stillborn sisters with a multiple congenital anomaly syndrome characterized by coarse facies with cloudy corneae, diaphragmatic defects, absence of lung lobulation, and distal limb deformities. A sporadic case was reported by Goddeeris et al. (1980). Fitch (1988) claimed that she and her colleagues were the first to describe this disorder. In 1978 they reported a single infant, born of second-cousin parents, who had absent left hemidiaphragm, hydrocephalus, arhinencephaly, and cardiovascular anomalies.

- Lubinsky et al. (1983) reported a brother and sister with Fryns syndrome who both died in the neonatal period. Facial anomalies included broad nasal bridge, microretrognathia, abnormal helices, and cleft palate. Other features included distal digital hypoplasia, lung hypoplasia, and urogenital abnormalities, including shawl scrotum, uterus bicornis, and renal cysts. They were discordant for diaphragmatic hernia, cleft lip, and Dandy–Walker anomaly.

- Meinecke and Fryns (1985) reported an affected child; consanguinity of the parents supported recessive inheritance. They noted that a diaphragmatic defect had been described in 4 of the 5 reported cases and lung hypoplasia in all. Young et al. (1986) reported a sixth case. The male infant survived for 12 days. These authors listed corneal clouding, camptodactyly with hypoplastic nails, and abnormalities of the diaphragm as cardinal features.

- Samueloff et al. (1987) described a family in which all 4 children had Fryns syndrome and neonatal mortality. Features included hypoplastic lungs, cleft palate, retrognathia, micrognathism, small thorax, diaphragmatic hernia, distal limb hypoplasia, and early onset of polyhydramnios with premature delivery. Schwyzer et al. (1987) described an affected infant whose parents were second cousins.

- Moerman et al. (1988) described infant brother and sister with the syndrome of diaphragmatic hernia, abnormal face, and distal limb anomalies. Both died shortly after birth with severe respiratory distress. Ultrasonography demonstrated fetal hydrops, diaphragmatic hernia, and striking dilatation of the cerebral ventricles in both infants. Post-mortem examination showed Dandy–Walker malformation, ventricular septal defect, and renal cystic dysplasia.

- Cunniff et al. (1990) described affected brothers and 3 other cases, bringing the total reported cases of Fryns syndrome to 25. One of the affected brothers was still alive at the age of 24 months. Bilateral diaphragmatic hernias had been repaired on the first day of life. He required extracorporeal membrane oxygenation therapy for 5 days and oscillatory therapy for 3 months. Ventriculoperitoneal shunt was required because of slowly progressive hydrocephalus. Scoliosis was associated with extranumerary vertebral bodies and 13 ribs. Because of delayed gastric emptying, a gastrostomy tube was inserted. In addition, because of persistent chylothorax, he underwent decortication of the right lung and oversewing of the thoracic duct.

- Kershisnik et al. (1991) suggested that osteochondrodysplasia is a feature of Fryns syndrome.

- Willems et al. (1991) suggested that a diaphragmatic hernia is not a necessary feature of Fryns syndrome. They described a child with all the usual features except for diaphragmatic hernia; the diaphragm was reduced to a fibrous web with little muscular component. Bartsch et al. (1995) presented 2 unrelated cases with a typical picture of Fryns syndrome but without diaphragmatic hernia. One of these patients was alive at the age of 14 months, but was severely retarded. Bamforth et al. (1987) and Hanssen et al. (1992) also described patients with this syndrome who survived the neonatal period. In the report of Hanssen et al. (1992), 2 older sibs had died in utero. The reports suggested that survival beyond the neonatal period is possible when the diaphragmatic defect and lung hypoplasia are not present. However, mental retardation has been present in all surviving patients.

- Vargas et al. (2000) reported a pair of monozygotic twins with Fryns syndrome discordant for severity of diaphragmatic defect. Both twins had macrocephaly, coarse facial appearance, hypoplasia of distal phalanges, and an extra pair of ribs. Twin A lacked an apparent diaphragmatic defect, and at 1 year of age had mild developmental delay. Twin B had a left congenital diaphragmatic hernia and died neonatally. The authors suggested that absence of diaphragmatic defect in Fryns syndrome may represent a subpopulation of more mildly affected patients.

- Aymé, "et al." (1989) described 8 cases of Fryns syndrome in France. The most frequent anomalies were diaphragmatic defects, lung hypoplasia, cleft lip and palate, cardiac defects, including septal defects and aortic arch anomalies, renal cysts, urinary tract malformations, and distal limb hypoplasia. Most patients also had hypoplastic external genitalia and anomalies of internal genitalia, including bifid or hypoplastic uterus or immature testes. The digestive tract was also often abnormal; duodenal atresia, pyloric hyperplasia, malrotation and common mesentery were present in about half of the patients. When the brain was examined, more than half were found to have Dandy–Walker anomaly and/or agenesis of the corpus callosum. A few patients demonstrated cloudy cornea. Histologically, 2 of 3 patients showed retinal dysplasia with rosettes and gliosis of the retina, thickness of the posterior capsule of the lens, and irregularities of Bowman membrane.

- Alessandri et al. (2005) reported a newborn from the Comores Islands with clinical features of Fryns syndrome without diaphragmatic hernia. They noted that diaphragmatic hernia is found in more than 80% of cases and that at least 13 other cases had been reported with an intact diaphragm.

- In a postneonatal survivor of Fryns syndrome, Riela et al. (1995) described myoclonus appearing shortly after birth, which was well controlled on valproate. Progressive cerebral and brainstem atrophy was noted on serial MRIs made at 3 months and after 6 months of age.

- Van Hove et al. (1995) described a boy with Fryns syndrome who survived to age 3 years and reviewed the outcome of other reported survivors (approximately 14% of reported cases). Survivors tended to have less frequent diaphragmatic hernia, milder lung hypoplasia, absence of complex cardiac malformation, and severe neurologic impairment. Their patient had malformations of gyration and sulcation, particularly around the central sulcus, and hypoplastic optic tracts beyond the optic chiasm associated with profound mental retardation.

- Fryns and Moerman (1998) reported a second-trimester male fetus with Fryns syndrome and midline scalp defects. The authors stated that the finding of a scalp defect in Fryns syndrome confirms that it is a true malformation syndrome with major involvement of the midline structures.

- Ramsing et al. (2000) described 2 sibships with 4 fetuses and 1 preterm baby of 31 weeks' gestation affected by a multiple congenital disorder suggestive of Fryns syndrome. In addition to the diaphragmatic defects and distal limb anomalies, they presented with fetal hydrops, cystic hygroma, and multiple pterygias. Two affected fetuses in 1 family showed severe craniofacial abnormalities with bilateral cleft lip and palate and cardiovascular malformation.

- Arnold et al. (2003) reported a male fetus with Fryns syndrome and additional abnormalities, in particular, multiple midline developmental defects including gastroschisis, central nervous system defects with left arrhinencephaly and cerebellar hypoplasia, midline cleft of the upper lip, alveolar ridge, and maxillary bone, and cleft nose with bilateral choanal atresia.

- Pierson et al. (2004) reviewed 77 reported patients with Fryns syndrome and summarized the abnormal eye findings identified in 12 of them. They also described 3 new patients with Fryns syndrome, 1 of whom demonstrated unilateral microphthalmia and cloudy cornea.

- Slavotinek et al. (2005) noted that Fryns syndrome may be the most common autosomal recessive syndrome in which congenital diaphragmatic hernia (see DIH2, 222400) is a cardinal feature. The autosomal recessive inheritance in Fryns syndrome contrasts with the sporadic inheritance for most patients with DIH.

A Bochdalek hernia is one of two forms of a congenital diaphragmatic hernia, the other form being Morgagni hernia. A Bochdalek hernia is a congenital abnormality in which an opening exists in the infant's diaphragm, allowing normally intra-abdominal organs (particularly the stomach and intestines) to protrude into the thoracic cavity. In the majority of patients, the affected lung will be deformed, and the resulting lung compression can be life-threatening. Bochdalek hernias occur more commonly on the posterior left side (85%, versus right side 15%). This type of hernia was first studied and documented by the Czech Anatomist and Pathologist, Vincenz Alexander Bochdalek (1801–1883).

Treatment for a diaphragmatic hernia usually involves surgery, with acute injuries often repaired with monofilament permanent sutures.

A scaphoid abdomen (sucked inwards) may be the presenting symptom in a newborn.

Additional symptoms include:

- anencephaly (failure of major sections of the brain to form)

- encephalocele (cranial contents protrudes from the skull)

- cyclopia (the two eye cavities fuse into one)

- agnathia

- cleft palate

- arthrogryposis

- clubfeet

- holoprosencephaly

- spina bifida

- low-set ears

- pulmonary hypoplasia

- omphalocele

- gastroschisis

- cardiovascular disorders

- diaphragmatic hernias

- gastrointestinal atresia

- single umbilical artery

- renal abnormalities

- genu recurvatum

- hydramnios

Pentalogy of Cantrell (or thoraco-abdominal syndrome) is a rare syndrome that causes defects involving the diaphragm, abdominal wall, pericardium, heart and lower sternum.

Its prevalence is less than 1 in 1000000.

It was characterized in 1958.

A locus at Xq25-26 has been described.

People with pectus carinatum usually develop normal hearts and lungs, but the malformation may prevent these from functioning optimally. In moderate to severe cases of pectus carinatum, the chest wall is rigidly held in an outward position. Thus, respirations are inefficient and the individual needs to use the accessory muscles for respiration, rather than normal chest muscles, during strenuous exercise. This negatively affects gas exchange and causes a decrease in stamina. Children with pectus malformations often tire sooner than their peers, due to shortness of breath and fatigue. Commonly concurrent is mild to moderate asthma.

Some children with pectus carinatum also have scoliosis (i.e., curvature of the spine). Some have mitral valve prolapse, a condition in which the heart mitral valve functions abnormally. Connective tissue disorders involving structural abnormalities of the major blood vessels and heart valves are also seen. Although rarely seen, some children have other connective tissue disorders, including arthritis, visual impairment and healing impairment.

Apart from the possible physiologic consequences, pectus malformations can have a significant psychologic impact. Some people, especially those with milder cases, live happily with pectus carinatum. For others, though, the shape of the chest can damage their self-image and confidence, possibly disrupting social connections and causing them to feel uncomfortable throughout adolescence and adulthood. As the child grows older, bodybuilding techniques may be useful for balancing visual impact.

A less common variant of pectus carinatum is "pectus arcuatum" (also called type 2 pectus excavatum, chondromanubrial malformation or Currarino–Silverman syndrome or pouter pigeon malformation), which produces a manubrial and upper sternal protrusion, particularly also at the sternal angle. Pectus arcuatum is often confused with a combination of pectus carinatum and pectus excavatum, but in pectus arcuatum the visual appearance is characterized by a protrusion of the costal cartilages and there is no depression of the sternum.

The affected infant tends to be short, with a disproportionately large head. The fetal head of Infants born with iniencephaly are hyperextended while the foramen magnum is enlarged and opens through the widened pedicles. The defective neural arches directly into the upper cervical reach of the spinal canal, causing the formation of a common cavity between most of the spinal cord and the brain. The skin of the anterior chest is connected directly to the face, bypassing the formation of a neck, while the scalp is directly connected to the skin of the back. Because of this, those born with this anomaly either have a highly shortened neck or no neck at all. This causes extreme retroflexion, or backward bending, of the head in a "star-gazing" fashion. The spine is severely distorted as well along with significant shortening due to marked lordosis. The vertebrae, especially cervical, are fused together in abnormal shapes and their numbers are reduced. The spinal cord is almost always defective while the ventricular system is often dilated and the cortex is thinned. Sometimes, in the case of iniencephaly apertus, an encephalocele (sac-like protrusions of the brain through an opening in the cranium) forms.

This condition exists in a variety of forms, ranging from partial absence of the tail bone regions of the spine to absence of the lower vertebrae, pelvis and parts of the thoracic and/or lumbar areas of the spine. In some cases where only a small part of the spine is absent, there may be no outward sign of the condition. In cases where more substantial areas of the spine are absent, there may be fused, webbed, or smaller lower extremities and paralysis. Bowel and bladder control is usually affected.

Lung hernia (Sibson hernia) is a protrusion of lung outside of thoracic wall. In 20% patients with lung hernia, the incidence is congenital. In 80% of the cases, the hernia is noted after chest trauma, thoracic surgery or certain pulmonary diseases. Congenital hernia occurs because of the weakness of the suprapleural membrane or neck muscles. In pulmonary diseases such as asthma, frequent coughing can lead to high intra thoracic pressure, causing the lung to herniate out. Lung hernia may occur near the neck (cervical), between the ribs (intercostal), near the vertebrae (paravertebral) or near the sternum (parasternal).

Ectopia cordis (Greek: ""away / out of place"" + Latin: ""heart"") is a congenital malformation in which the heart is abnormally located either partially or totally outside of the thorax. The ectopic heart can be found along a spectrum of anatomical locations, including the neck, chest, or abdomen. In most cases, the heart protrudes outside the chest through a split sternum.

Pectus carinatum is an overgrowth of costal cartilage causing the sternum to protrude forward. It primarily occurs among four different patient groups, and males are more frequently affected than females. Most commonly, pectus carinatum develops in 11-to-14-year-old pubertal males undergoing a growth spurt. Some parents report that their child's pectus carinatum seemingly popped up overnight. Second most common is the presence of pectus carinatum at or shortly after birth. The condition may be evident in newborns as a rounded anterior chest wall. As the child reaches age 2 or 3 years of age, the outward sternal protrusion becomes more pronounced. Pectus carinatum can also be caused by vitamin D deficiency in children (Rickets) due to deposition of unmineralized osteoid. Least common is a pectus carinatum malformation following open-heart surgery or in children with poorly controlled bronchial asthma.

Pectus carinatum is generally a solitary, non-syndromic abnormality. However, the condition may be present in association with other syndromes: Turner syndrome, Noonan syndrome, Loeys-Dietz syndrome, Marfan syndrome, Ehlers-Danlos syndrome, Morquio syndrome, trisomy 18, trisomy 21, homocystinuria, osteogenesis imperfecta, multiple lentigines syndrome (LEOPARD syndrome), Sly syndrome (mucopolysaccharidosis type VII), and scoliosis.

In about 25% of cases of pectus carinatum, the patient has a family member with the condition.

The prognosis of ectopia cordis depends on classification according to three factors:

1. Location of the defect

- Cervical

- Thoracic

- Thoracoabdominal

- Abdominal

2. Extent of the cardiac displacement

3. Presence or absence of intracardiac defects

Some studies have suggested a better prognosis with surgery in cases of thoracoabdominal ectopia cordis or less severe pentalogy of Cantrell. In general, the prognosis for ectopia cordis is poor—most cases result in death shortly after birth due to infection, hypoxemia, or cardiac failure.

Prenatal Diagnosis:

- Aymé, "et al." (1989) reported prenatal diagnosis of Fryns syndrome by sonography between 24 and 27 weeks.

- Manouvrier-Hanu et al. (1996) described the prenatal diagnosis of Fryns syndrome by ultrasonographic detection of diaphragmatic hernia and cystic hygroma. The diagnosis was confirmed after termination of the pregnancy. The fetus also had 2 erupted incisors; natal teeth had not been mentioned in other cases of Fryns syndrome.

Differential Diagnosis:

- McPherson et al. (1993) noted the phenotypic overlap between Fryns syndrome and the Pallister–Killian syndrome (601803), which is a dysmorphic syndrome with tissue-specific mosaicism of tetrasomy 12p.

- Veldman et al. (2002) discussed the differentiation between Fryns syndrome and Pallister–Killian syndrome, noting that differentiation is important to genetic counseling because Fryns syndrome is an autosomal recessive disorder and Pallister–Killian syndrome is usually a sporadic chromosomal aberration. However, discrimination may be difficult due to the phenotypic similarity. In fact, in some infants with 'coarse face,' acral hypoplasia, and internal anomalies, the initial diagnosis of Fryns syndrome had to be changed because mosaicism of isochromosome 12p was detected in fibroblast cultures or kidney tissue. Although congenital diaphragmatic hernia is a common finding in both syndromes, bilateral congenital diaphragmatic hernia had been reported only in patients with Fryns syndrome until the report of the patient with Pallister–Killian syndrome by Veldman et al. (2002).

- Slavotinek (2004) reviewed the phenotypes of 52 reported cases of Fryns syndrome and reevaluated the diagnostic guidelines. She concluded that congenital diaphragmatic hernia and distal limb hypoplasia are strongly suggestive of Fryns syndrome, with other diagnostically relevant findings including pulmonary hypoplasia, craniofacial dysmorphism, polyhydramnios, and orofacial clefting. Slavotinek (2004) stated that other distinctive anomalies not mentioned in previous guidelines include ventricular dilatation or hydrocephalus, agenesis of the corpus callosum, abnormalities of the aorta, dilatation of the ureters, proximal thumbs, and broad clavicles.

Caudal regression syndrome or sacral agenesis (or hypoplasia of the sacrum) is a congenital disorder in which there is abnormal fetal development of the lower spine—the caudal partition of the spine.

It occurs at a rate of approximately one per 25,000 live births.

Among the signs and symptoms demonstrated, by this condition are the following:

- Arachnodactyly

- Congenital diaphragmatic hernia

- Mental dysfunction

- Keratoconus

- Aortic regurgitation

- Blepharophimosis