Different features of the dysostosis are significant. Radiological imaging helps confirm the diagnosis. During gestation (pregnancy), clavicular size can be calculated using available nomograms. Wormian bones can sometimes be observed in the skull.

Diagnosis of CCD spectrum disorder is established in an individual with typical clinical and radiographic findings and/or by the identification of a heterozygous pathogenic variant in RUNX2 (CBFA1).

The diagnosis of this condition can be done via x-rays (with lack of normal distance L1 to L5), and additionally genetic testing is available to ascertain hypochondroplasia However, the physical characteristics(physical finding) is one of the most important in determining the condition.

There are multiple classifications for the triphalangeal thumb. The reason for these different classifications is the heterogeneity in appearance of the TPT.

The classification according to Wood describes the shape of the extra phalanx: delta (Fig. 4), rectangular or full phalanx (Table 1). With the classification made by Buck-Gramcko a surgical treatment can be chosen (Table 1). Buck-Gramcko differentiates between six different shapes of the extra phalanx and associated malformations.

Table 1: Classifications of Wood and Buck-Gramcko

There are several classifications for cleft hand, but the most used classification is described by Manske and Halikis see table 3. This classification is based on the first web space. The first web space is the space between the thumb and the index.

Table 3: Classification for cleft hand described by Manske and Halikis

Surgical treatment of the cleft hand is based on several indications:

Improving function

- Absent thumb

- Deforming syndactyly (mostly between digits of unequal length like index and thumb)

- Transverse bones (this will progress the deformity; growth of these bones will widen the cleft)

- Narrowed first webspace

- The feet

Aesthetical aspects

- Reducing deformity

Most children with symbrachydactyly have excellent function in daily activities. Due to the length of their arm, they do not qualify for most artificial limbs. However, some adaptive prosthetics and equipment for sports and leisure activities may be helpful when the child is older. Children who demonstrate some functional movement in their remaining fingers and within the palm are evaluated for possible surgery such as toe transfers.

The goals of surgical treatment are: reducing length of the thumb, creating a good functioning, a stable and non deviated joint and improving the position of the thumb if necessary. Hereby improving function of the hand and thumb.

In general the surgical treatment is done for improvement of the thumb function. However, an extra advantage of the surgery is the improvement in appearance of the thumb. In the past, surgical treatment of the triphalangeal thumb was not indicated, but now it is generally agreed that operative treatment improves function and appearance. Because an operation was not indicated in the past, there’s still a population with an untreated triphalangeal thumb. The majority of this population doesn’t want surgery, because the daily functioning of the hand is good. The main obstacle for the untreated patients might not be the diminished function, but the appearance of the triphalangeal thumb.

The timing of surgery differs between Wood and Buck-Gramcko. Wood advises operation between the age of six months and two years, while Buck-Gramcko advises to operate for all indications before the age of six years.

- For TPT types I and II of the Buck-Gramcko classification, the surgical treatment typically consists of removing the extra phalanx and reconstructing the ulnar collateral ligament and the radial collateral ligament if necessary.

- For type III of Buck-Gramcko classification proposable surgical treatments:

- For type IV of Buck-Gramcko classification the surgical treatment typically consists of an osteotomy which reduces the middle phalanx and arthrodesis of the DIP. This gives a shortening of 1 to 1.5 cm. In most cases, this technique is combined with a shortening, rotation and palmar abduction osteotomy at metacarpal level to correct for position and length of the thumb. The extensor tendons and the intrinsic muscles are shortened as well.

- For type V of the Buck-Gramcko classification the surgical treatment proposably consists of a "pollicization". With a pollicization the malpositioned thumb is repositioned, rotated and shortened, the above-described rotation reduction osteotomy of the first metacarpal can be performed as well.

- For type VI of the Buck-Gramcko classification, the surgical treatment typically consists of removing the additional mostly hypoplastic thumb(s). Further procedures of reconstruction of the triphalangeal thumb are performed according to the shape of the extra phalanx as described above.

Diagnosis is based on physical examination including radiographs of the hands and feet and imaging studies of the kidneys, bladder, and female reproductive tract. HOXA13 is the only gene known to be associated with HFGS. Approximately 60% of mutations are polyalanine expansions. Molecular genetic testing is clinically available.

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.

Surgery is an option to correct some of the morphological changes made by Liebenberg Syndrome. Cases exist where surgery is performed to correct radial deviations and flexion deformities in the wrist. A surgery called a carpectomy has been performed on a patient whereby a surgeon removes the proximal row of the carpal bones. This procedure removes some of the carpal bones to create a more regular wrist function than is observed in people with this condition.

Surgical correction is recommended when a constriction ring results in a limb contour deformity, with or without lymphedema.

Life expectancy for individuals with hypochondroplasia is normal; the maximum height is about 147 cm or 4.8 ft.

The constellation of anomalies seen with Nasodigitoacoustic syndrome result in a distinct diagnosis. The diagnostic criteria for the disorder are broad distal phalanges of the thumbs and big toes, accompanied by a broad and shortened nose, sensorineural hearing loss and developmental delay, with predominant occurrence in males.

Additional findings that may be present in HFGS according to the latest research are:

- Limited metacarpophalangeal flexion of the thumb or limited ability to oppose the thumb and fifth finger

- Hypoplastic thenar eminences

- Medial deviation of the great toe (hallux varus), a useful diagnostic sign when present

- Small great toenail

- Fifth-finger clinodactyly, secondary to a shortened middle phalanx

- Short feet

- Altered dermatoglyphics of the hands; when present, primarily involving distal placement of the axial triradius, lack of thenar or hypothenar patterning, low arches on the thumbs, thin ulnar loops (deficiency of radial loops and whorls), and a greatly reduced ridge count on the fingers

Radiographic findings

- Hypoplasia of the distal phalanx and first metacarpal of the thumbs and great toes

- Pointed distal phalanges of the thumb

- Lack of normal tufting of the distal phalanges of the great toes

- Fusions of the cuneiform to other tarsal bones or trapezium-scaphoid fusion of the carpals

- Short calcaneus

- Occasional bony fusions of the middle and distal phalanges of the second, third, fourth, or fifth toes

- Delayed carpal or tarsal maturation

- Metacarpophalangeal profile reflecting shortening of the first metacarpal, the first and second phalanges, and the second phalanx of the second and fifth digits

Urogenital Defects

Females may have the following:

- Vesicoureteral reflux secondary to ureteric incompetence

- Ectopic ureteral orifices

- Trigonal hypoplasia

- Hypospadiac urethra

- Subsymphyseal epispadias

- Patulous urethra

- Urinary incontinence (related to structural anomalies and weakness of the bladder sphincter muscle)

- Small hymenal opening

- Various degrees of incomplete Müllerian fusion with or without two cervices or a longitudinal vaginal septum

Males may have the following:

- Retrograde ejaculation (related to structural anomalies and weakness of the bladder sphincter muscle)

The complete or partial absence of the pectoralis muscle is the malformation that defines Poland Syndrome. It can be treated by inserting a custom implant designed by CAD (computer aided design). A 3D reconstruction of the patient's chest is performed from a medical scanner to design a virtual implant perfectly adapted to the anatomy of each one. The implant is made of medical silicone unbreakable rubber. This treatment is purely cosmetic and does not make up for the patient's imbalanced upper body strength.

The Poland syndrome malformations being morphological, correction by custom implant is a first-line treatment. This technique allows a wide variety of patients to be treated with good outcomes. Poland Syndrome can be associated with bones, subcutaneous and mammary atrophy: if the first, as for pectus excavatum, is successfully corrected by a custom implant, the others can require surgical intervention such as lipofilling or silicone breast implant, in a second operation.

Three main support groups of this syndrome are the ASGA in Australia, The Association for Children with Genetic Disorders in Poland, and the Association of People of Genetic Disorders in Greece.

Nasodigitoacoustic syndrome is similar to several syndromes that share its features. Brachydactyly of the distal phalanges, sensorineural deafness and pulmonary stenosis are common with Keutel syndrome. In Muenke syndrome, developmental delay, distal brachydactyly and sensorineural hearing loss are reported; features of Teunissen-Cremers syndrome include nasal aberrations and broadness of the thumbs and big toes, also with brachydactyly. Broad thumbs and big toes are primary characteristics of Rubinstein syndrome.

Around 5 years of age, surgical correction may be necessary to prevent any worsening of the deformity. If the mother has dysplasia, caesarian delivery may be necessary. Craniofacial surgery may be necessary to correct skull defects. Coxa vara is treated by corrective femoral osteotomies. If there is brachial plexus irritation with pain and numbness, excision of the clavicular fragments can be performed to decompress it. In case of open fontanelle, appropriate headgear may be advised by the orthopedist for protection from injury.

Early intervention is considered important. For infants, breathing and feeding difficulties, are monitored. Therapies used are "symptomatic and supportive."

Symbrachydactyly is a congenital abnormality, characterized by limb anomalies consisting of brachydactyly, cutaneous syndactyly and global hypoplasia of the hand or foot. In many cases, bones will be missing from the fingers and some fingers or toes may be missing altogether. The ends of the hand may have "nubbins"—small stumps where the finger would have developed, which may have tiny residual nails.

Symbrachydactyly has been reported to appear without other combined limb anomalies and usually in one arm in 1 in 30,000 births to 1 in 40,000 births.

The cause of symbrachydactyly is unknown. One possible cause might be an interruption of the blood supply to the developing arm at four to six weeks of pregnancy. There is no link to anything the mother did or did not do during pregnancy. There is also no increased risk of having another child with the same condition or that the child will pass the condition on to his or her children.

In most cases, children born with symbrachydactyly are able to adapt to their physical limitations and experience a fully functional life with no treatment. Most children with this condition can use their hands well enough to do all the usual things children do. Possible treatment includes surgery or a routine of regularly stretching the fingers.

The key problem is the early fusion of the skull, which can be corrected by a series of surgical procedures, often within the first three months after birth. Later surgeries are necessary to correct respiratory and facial deformities.

At the beginning of the surgery a tourniquet will be applied to the limb. A tourniquet compresses and control the arterial and venous circulation for about 2 hours. The constriction band must be dissected very carefully to avoid damaging the underlying neurovasculature. When the constriction band is excised, there will be a direct closure. This allows the fatty tissue to naturally reposition itself under the skin.

“With complete circumferential constriction bands, it is recommended that a two-stage correction approach be used. At the first operation, one-half of the circumference is excised and the other one-half can be excised after three to six months. This will avoid any problems to the distal circulation in the limb, which may already be compromised. Lymphedema, when present, will significantly improve within a few weeks of the first surgery.”

For the direct closure of the defect after dissecting a constriction band there are two different techniques:

1. Triangular flaps; For this technique the circumference between the two borders must be measured. Depending on the difference the number of triangular flaps can be decided. With a triangular flap you can create more skin.

2. Z/W-plasty; “Z-plasty is a plastic surgery technique that is used to improve the functional and cosmetic appearance of scars. It can elongate a contracted scar or rotate the scar tension line. The middle line of the Z-shaped incision (the central element) is made along the line of greatest tension or contraction, and triangular flaps are raised on opposite sides of the two ends and then transposed.”

In rare cases, if diagnosed in utero, fetal surgery may be considered to save a limb that is in danger of amputation or other deformity. This operation has been successfully performed on fetuses as young as 22 weeks. The Melbourne's Monash Medical Centre in Australia, as well as multiple facilities in the United States of America, have performed successful amniotic band release surgery.

Hypophalangism is a congenital absence of one or more phalanges (bones of the fingers and toes).

In the above brachydactyly syndromes, short digits are the most prominent of the anomalies, but in many other syndromes (Down syndrome, Rubinstein-Taybi syndrome, etc.), brachydactyly is a minor feature compared to the other anomalies or problems comprising the syndrome.

The surgery takes place under general anaesthesia and lasts less than 1 hour. The surgeon prepares the locus to the size of the implant after performing a 8-cm axillary incision and inserts the implant beneath the skin. The closure is made in 2 planes.

The implant will replace the pectoralis major muscle, thus enabling the thorax to be symmetrical and, in women, the breast as well. If necessary, especially in the case of women, a second operation will complement the result by the implantation of a breast implant and / or lipofilling.

Lipomodelling is progressively used in the correction of breast and chest wall deformities. In Poland syndrome, this technique appears to be a major advance that will probably revolutionize the treatment of severe cases. This is mainly due to its ability to achieve previously unachievable quality of reconstruction with minimal scaring.